Workflow Inputs

OpenStudio-HPXML requires a building description in an HPXML file format. HPXML is an open data standard for collecting and transferring home energy data. Using HPXML files reduces the complexity and effort for software developers to leverage the EnergyPlus simulation engine.

Using HPXML

HPXML is an flexible and extensible format, where nearly all elements in the schema are optional and custom elements can be included. Because of this, a stricter set of requirements for the HPXML file have been developed for purposes of running EnergyPlus simulations.

HPXML files submitted to OpenStudio-HPXML undergo a two step validation process:

1. Validation against the HPXML Schema

The HPXML XSD Schema can be found at HPXMLtoOpenStudio/resources/hpxml_schema/HPXML.xsd. XSD Schemas are used to validate what elements/attributes/enumerations are available, data types for elements/attributes, the number/order of children elements, etc.

2. Validation using Schematron

The Schematron document for the EnergyPlus use case can be found at HPXMLtoOpenStudio/resources/hpxml_schematron/EPvalidator.sch. Schematron is a rule-based validation language, expressed in XML using XPath expressions, for validating the presence or absence of inputs in XML files. As opposed to an XSD Schema, a Schematron document validates constraints and requirements based on conditionals and other logical statements. For example, if an element is specified with a particular value, the applicable enumerations of another element may change.

OpenStudio-HPXML automatically validates the HPXML file against both the XSD and Schematron documents and reports any validation errors, but software developers may find it beneficial to also integrate validation into their software.

Input Defaults

A large number of elements in the HPXML file are optional and can be defaulted. Default values, equations, and logic are described throughout this documentation.

For example, suppose a HPXML file has a refrigerator defined as follows:

<Refrigerator>
  <SystemIdentifier id='Refrigerator1'/>
</Refrigerator>

Default values would be used for the refrigerator energy use, location, and schedule:

<Refrigerator>
  <SystemIdentifier id='Refrigerator1'/>
  <Location dataSource='software'>conditioned space</Location>
  <RatedAnnualkWh dataSource='software'>691.0</RatedAnnualkWh>
  <PrimaryIndicator dataSource='software'>true</PrimaryIndicator>
  <extension>
    <UsageMultiplier dataSource='software'>1.0</UsageMultiplier>
    <WeekdayScheduleFractions dataSource='software'>0.040, 0.039, 0.038, 0.037, 0.036, 0.036, 0.038, 0.040, 0.041, 0.041, 0.040, 0.040, 0.042, 0.042, 0.042, 0.041, 0.044, 0.048, 0.050, 0.048, 0.047, 0.046, 0.044, 0.041</WeekdayScheduleFractions>
    <WeekendScheduleFractions dataSource='software'>0.040, 0.039, 0.038, 0.037, 0.036, 0.036, 0.038, 0.040, 0.041, 0.041, 0.040, 0.040, 0.042, 0.042, 0.042, 0.041, 0.044, 0.048, 0.050, 0.048, 0.047, 0.046, 0.044, 0.041</WeekendScheduleFractions>
    <MonthlyScheduleMultipliers dataSource='software'>0.837, 0.835, 1.084, 1.084, 1.084, 1.096, 1.096, 1.096, 1.096, 0.931, 0.925, 0.837</MonthlyScheduleMultipliers>
  </extension>
</Refrigerator>

These defaults will be reflected in the EnergyPlus simulation results.

Note

The OpenStudio-HPXML workflow generally treats missing elements differently than missing values. For example, if there is no Refrigerator element defined, the simulation will proceed without refrigerator energy use. On the other hand, if there is a Refrigerator element but with no values defined (i.e., no Location or RatedAnnualkWh), it is assumed that a refrigerator exists but its properties are unknown, so they will be defaulted in the model.

See HPXML Defaults for information on how default values can be inspected.

HPXML Software Info

High-level simulation inputs are entered in /HPXML/SoftwareInfo.

HPXML Simulation Control

EnergyPlus simulation controls are entered in /HPXML/SoftwareInfo/extension/SimulationControl.

Element	Type	Units	Constraints	Required	Default	Notes
Timestep	integer	minutes	Divisor of 60	No	60 (1 hour)	Timestep
BeginMonth	integer		>= 1, <= 12 [1]	No	1 (January)	Run period start date
BeginDayOfMonth	integer		>= 1, <= 31	No	1	Run period start date
EndMonth	integer		>= 1, <= 12	No	12 (December)	Run period end date
EndDayOfMonth	integer		>= 1, <= 31	No	31	Run period end date
CalendarYear	integer		> 1600 [2]	No	2007 (for TMY weather) [3]	Calendar year (for start day of week)
AdvancedResearchFeatures	element			No	<none>	Features used for advanced research modeling

[1]

BeginMonth/BeginDayOfMonth date must occur before EndMonth/EndDayOfMonth date (e.g., a run period from 10/1 to 3/31 is invalid).

[2]

If a leap year is specified (e.g., 2008), the EPW weather file must contain 8784 hours.

[3]

CalendarYear only applies to TMY (Typical Meteorological Year) weather. For AMY (Actual Meteorological Year) weather, the AMY year will be used regardless of what is specified.

To enable advanced research features, additional information is entered in /HPXML/SoftwareInfo/extension/SimulationControl/AdvancedResearchFeatures.

These features may require shorter timesteps, allow more sophisticated simulation control, and/or impact simulation runtime.

Element	Type	Units	Constraints	Required	Default	Notes
TemperatureCapacitanceMultiplier	double		> 0	No	7.0 [4]	Multiplier on air heat capacitance [5]
OnOffThermostatDeadbandTemperature	double	F	> 0 [6]	No		Temperature difference between cut-in and cut-out temperature for HVAC operation [7]
HeatPumpBackupCapacityIncrement	double	Btu/hr	> 0 [8]	No		Capacity increment of multi-stage heat pump backup systems [9]
GroundToAirHeatPumpModelType	string		See [10]	No	standard	Ground-to-air heat pump system model type [11]

[4]

The default value of 7 is an average value found in the literature when calibrating timeseries EnergyPlus indoor temperatures to field data.

[5]

TemperatureCapacitanceMultiplier affects the transient calculation of indoor air temperatures. Values greater than 1.0 have the effect of smoothing or damping the rate of change in the indoor air temperature from timestep to timestep. This heat capacitance effect is modeled on top of any other individual mass inputs (e.g., furniture mass, partition wall mass, interior drywall, etc.) in the HPXML.

[6]

OnOffThermostatDeadbandTemperature is currently only allowed with a 1 minute timestep. Currently only supports homes with at most one cooling system (including heat pumps) serving 100% of the cooling load and at most one heating system (including heat pumps) serving 100% of the heating load (i.e., FractionHeatLoadServed and FractionCoolLoadServed are 1.0). Applies to single speed and two speed AC/ASHP only.

[7]

An on/off thermostat deadband temperature is applied to both heating and cooling. Typical values are between 2-4 F, with actual values being specific to the thermostat installed. Note that thermostat deadbands are two sided. As an example, if you had a heating setpoint of 71 F and a 2 F deadband, the heating equipment will turn on when the space temperature hits 70 F and off when it hits 72 F. When this feature is enabled, the model will also explicitly model cycling, such that it will take several minutes for the HVAC to reach full capacity for single and two speed AC/ASHP systems, and time-based realistic staging (stay at low speed for 5 minutes before transitioning to the higher stage, and stay at high speed until cut-out deadband temperature is reached) for two speed AC/ASHP systems. This feature should only be used if detailed power profiles and loads are required. Common use cases for this feature are when modeling advanced controls, such as a Home Energy Management System, or if performing co-simulation with a grid model.

[8]

HeatPumpBackupCapacityIncrement is currently only allowed with a 1 minute timestep.

[9]

HeatPumpBackupCapacityIncrement allows modeling multi-stage electric heat pump backup with time-based staging. If not provided, the heat pump backup is modeled with a single stage.

[10]

GroundToAirHeatPumpModelType choices are “standard” and “experimental”.

[11]

Use “standard” for standard ground-to-air heat pump modeling. Use “experimental” for an improved model that better accounts for coil staging. The “experimental” ground-to-air heat pump models with desuperheater are not supported yet, see Desuperheater.

HPXML Emissions Scenarios

One or more emissions scenarios can be entered as an /HPXML/SoftwareInfo/extension/EmissionsScenarios/EmissionsScenario. If not entered, emissions will not be calculated.

Element	Type	Units	Constraints	Required	Default	Notes
Name	string			Yes		Name of the scenario (which shows up in the output file)
EmissionsType	string		See [12]	Yes		Type of emissions (e.g., CO2e)
EmissionsFactor	element			See [13]		Emissions factor(s) for a given fuel type; multiple are allowed

[12]

EmissionsType can be anything. But if certain values are provided (e.g., “CO2e”), then some emissions factors can be defaulted as described further below.

[13]

EmissionsFactor is required for electricity and optional for all non-electric fuel types.

See Annual Outputs and Timeseries Outputs for descriptions of how the calculated emissions appear in the output files.

Electricity Emissions

For each scenario, electricity emissions factors must be entered as an /HPXML/SoftwareInfo/extension/EmissionsScenarios/EmissionsScenario/EmissionsFactor.

Element	Type	Units	Constraints	Required	Default	Notes
FuelType	string		electricity	Yes		Emissions factor fuel type
Units	string		See [14]	Yes		Emissions factor units
Value or ScheduleFilePath	double or string		See [15]	Yes		Emissions factor annual value or schedule file with hourly values

[14]

Units choices are “lb/MWh” and “kg/MWh”.

[15]

ScheduleFilePath must point to a CSV file with 8760 numeric hourly values. Sources of electricity emissions data include NREL’s Cambium database and EPA’s eGRID.

If an electricity schedule file is used, additional information can be entered in the /HPXML/SoftwareInfo/extension/EmissionsScenarios/EmissionsScenario/EmissionsFactor.

Element	Type	Units	Constraints	Required	Default	Notes
NumberofHeaderRows	integer	#	>= 0	No	0	Number of header rows in the schedule file
ColumnNumber	integer	#	>= 1	No	1	Column number of the data in the schedule file

Fuel Emissions

For each scenario, fuel emissions factors can be optionally entered as an /HPXML/SoftwareInfo/extension/EmissionsScenarios/EmissionsScenario/EmissionsFactor.

Element	Type	Units	Constraints	Required	Default	Notes
FuelType	string		See [16]	Yes		Emissions factor fuel type
Units	string		See [17]	Yes		Emissions factor units
Value	double			Yes		Emissions factor annual value

[16]

FuelType choices are “natural gas”, “propane”, “fuel oil”, “coal”, “wood”, and “wood pellets”.

[17]

Units choices are “lb/MBtu” and “kg/MBtu” (million Btu).

Default Values

If EmissionsType is “CO2e”, “NOx” or “SO2” and a given fuel’s emissions factor is not entered, they will be defaulted as follows.

Fuel Type	CO2e [lb/MBtu]	NOx [lb/MBtu]	SO2 [lb/MBtu]
natural gas	147.3	0.0922	0.0006
propane	177.8	0.1421	0.0002
fuel oil	195.9	0.1300	0.0015
coal	–	–	–
wood	–	–	–
wood pellets	–	–	–

Default values in lb/MBtu (million Btu) are from ANSI/RESNET/ICC 301-2022 Addendum B and include both combustion and pre-combustion (e.g., methane leakage for natural gas) emissions.

If no default value is available, a warning will be issued.

HPXML Utility Bill Scenarios

One or more utility bill scenarios can be entered as an /HPXML/SoftwareInfo/extension/UtilityBillScenarios/UtilityBillScenario. If not entered, utility bills will not be calculated.

Element	Type	Units	Constraints	Required	Default	Notes
Name	string			Yes		Name of the scenario (which shows up in the output file)
UtilityRate	element			No		Utility rate(s) for a given fuel type; multiple are allowed
PVCompensation	element			No		PV compensation information

See Utility Bill Outputs for a description of how the calculated utility bills appear in the output files.

Electricity Rates

For each scenario, electricity rates can be optionally entered as an /HPXML/SoftwareInfo/extension/UtilityBillScenarios/UtilityBillScenario/UtilityRate. Electricity rates can be entered using Simple inputs or Detailed inputs.

Simple

For simple utility rate structures, inputs can be entered using a fixed charge and a marginal rate.

Element	Type	Units	Constraints	Required	Default	Notes
FuelType	string		electricity	Yes		Fuel type
FixedCharge	double	$/month		No	12.0	Monthly fixed charge [18]
MarginalRate	double	$/kWh		No	See [19]	Marginal flat rate

[18]

If running Whole SFA/MF Buildings, the fixed charge will apply to every dwelling unit in the building.

[19]

If MarginalRate not provided, defaults to state, regional, or national average based on 2022 EIA SEDS data that can be found at ReportUtilityBills/resources/simple_rates/pr_all_update.csv.

Detailed

For detailed utility rate structures, inputs can be entered using a tariff JSON file.

Element	Type	Units	Constraints	Required	Default	Notes
FuelType	string		electricity	Yes		Fuel type
TariffFilePath	string			Yes		Path to tariff JSON file [20]

[20]

TariffFilePath must point to a JSON file with utility rate structure information. Tariff files can describe flat, tiered, time-of-use, tiered time-of-use, or real-time pricing rates. Sources of tariff files include OpenEI’s U.S. Utility Rate Database (URDB); a large set of residential OpenEI URDB rates for U.S. utilities are included at ReportUtilityBills/resources/detailed_rates/openei_rates.zip. Additional sample tariff files can be found in ReportUtilityBills/resources/detailed_rates. Tariff files are formatted based on OpenEI API version 7.

Fuel Rates

For each scenario, fuel rates can be optionally entered as an /HPXML/SoftwareInfo/extension/UtilityBillScenarios/UtilityBillScenario/UtilityRate.

Element	Type	Units	Constraints	Required	Default	Notes
FuelType	string		See [21]	Yes		Fuel type
FixedCharge	double	$/month		No	See [22]	Monthly fixed charge
MarginalRate	double	See [23]		No	See [24]	Marginal flat rate

[21]

FuelType choices are “natural gas”, “propane”, “fuel oil”, “coal”, “wood”, and “wood pellets”.

[22]

FixedCharge defaults to $12/month for natural gas and $0/month for other fuels.

[23]

MarginalRate units are $/therm for natural gas, $/gallon for propane and fuel oil, and $/kBtu for other fuels.

[24]

If MarginalRate not provided, defaults to state, regional, or national average based on 2022 EIA SEDS data that can be found at ReportUtilityBills/resources/simple_rates/pr_all_update.csv (except for coal, which is based on 2007 EIA SEDS data as EIA assumes there is zero residential sector coal consumption in the United States for 2008 forward and does not estimate a price).

PV Compensation

For each scenario, PV compensation information can be optionally entered in /HPXML/SoftwareInfo/extension/UtilityBillScenarios/UtilityBillScenario/PVCompensation.

Element	Type	Units	Constraints	Required	Default	Notes
CompensationType[NetMetering | FeedInTariff]	element			No	NetMetering	PV compensation type
MonthlyGridConnectionFee[Units="$/kW" or Units="$"]/Value	double			No	0	PV monthly grid connection fee

Net-Metering

If the PV compensation type is net-metering, additional information can be entered in /HPXML/SoftwareInfo/extension/UtilityBillScenarios/UtilityBillScenario/PVCompensation/CompensationType/NetMetering.

Element	Type	Units	Constraints	Required	Default	Notes
AnnualExcessSellbackRateType	string		See [25]	No	User-Specified	Net metering annual excess sellback rate type [26]
AnnualExcessSellbackRate	double	$/kWh		No [27]	0.03	User-specified net metering annual excess sellback rate [28]

[25]

AnnualExcessSellbackRateType choices are “User-Specified” and “Retail Electricity Cost”.

[26]

When annual PV production exceeds the annual building electricity consumption, this rate, which is often significantly below the retail rate, determines the value of the excess electricity sold back to the utility. This may happen to offset gas consumption, for example.

[27]

AnnualExcessSellbackRate is only used when AnnualExcessSellbackRateType=”User-Specified”.

[28]

Since modeled electricity consumption will not change from one year to the next, “indefinite rollover” of annual excess generation credit is best approximated by setting “User-Specified” and entering a rate of zero.

Feed-in Tariff

If the PV compensation type is feed-in tariff, additional information can be entered in /HPXML/SoftwareInfo/extension/UtilityBillScenarios/UtilityBillScenario/PVCompensation/CompensationType/FeedInTariff.

Element	Type	Units	Constraints	Required	Default	Notes
FeedInTariffRate	double	$/kWh		No	0.12	Feed-in tariff rate [29]

[29]

FeedInTariffRate applies to full (not excess) PV production. Some utilities/regions may have a feed-in tariff policy where compensation occurs for excess PV production (i.e., PV-generated electricity sent to the grid that is not immediately consumed by the building), rather than full PV production. OpenStudio-HPXML is currently unable to calculate utility bills for such a feed-in tariff policy.

HPXML Unavailable Periods

One or more unavailable periods (e.g., vacancies, power outages) can be entered as an /HPXML/SoftwareInfo/extension/UnavailablePeriods/UnavailablePeriod. If not entered, the simulation will not include unavailable periods.

Element	Type	Units	Constraints	Required	Default	Notes
ColumnName	string			Yes		Column name associated with unavailable_periods.csv below
BeginMonth	integer		>= 1, <= 12	Yes		Begin month
BeginDayOfMonth	integer		>= 1, <= 31	Yes		Begin day
BeginHourOfDay	integer		>= 0, <= 23	No	0	Begin hour
EndMonth	integer		>= 1, <= 12	Yes		End month
EndDayOfMonth	integer		>= 1, <= 31	Yes		End day
EndHourOfDay	integer		>= 1, <= 24	No	24	End hour
NaturalVentilation	string		See [30]	No	regular schedule	Natural ventilation availability

[30]

NaturalVentilation choices are “regular schedule”, “always available”, or “always unavailable”.

See the table below to understand which components are affected by an unavailable period with a given ColumnName. You can create an additional column in the CSV file to define another unavailable period type.

Schedule Name	Vacancy	Power Outage	No Space Heating	No Space Cooling
occupants	1	0	0	0
lighting_interior	1	1	0	0
lighting_exterior	1	1	0	0
lighting_garage	1	1	0	0
lighting_exterior_holiday	1	1	0	0
cooking_range	1	1	0	0
refrigerator	0	1	0	0
extra_refrigerator	0	1	0	0
freezer	0	1	0	0
dishwasher	1	1	0	0
clothes_washer	1	1	0	0
clothes_dryer	1	1	0	0
ceiling_fan	1	1	0	0
plug_loads_other	1	1	0	0
plug_loads_tv	1	1	0	0
plug_loads_vehicle	1	1	0	0
plug_loads_well_pump	1	1	0	0
fuel_loads_grill	1	1	0	0
fuel_loads_lighting	1	1	0	0
fuel_loads_fireplace	1	1	0	0
pool_pump	0	1	0	0
pool_heater	0	1	0	0
permanent_spa_pump	0	1	0	0
permanent_spa_heater	0	1	0	0
hot_water_fixtures	1	1	0	0
hot_water_recirculation_pump	1	1	0	0
general_water_use	1	0	0	0
space_heating	0	1	1	0
space_cooling	0	1	0	1
water_heater	0	1	0	0
dehumidifier	0	1	0	0
house_fan	0	1	0	0
kitchen_fan	1	1	0	0
bath_fan	1	1	0	0
whole_house_fan	1	1	0	0
battery_charging	0	1	0	0
battery_discharging	0	1	0	0
electric_vehicle_charging	1	1	0	0
electric_vehicle_discharging	1	1	0	0

Warning

It is not possible to eliminate all HVAC/DHW energy use (e.g. crankcase/defrost energy, water heater parasitics) in EnergyPlus during an unavailable period.

HPXML Electric Panel Calculations

To enable electric panel load calculations, one or more calculation types (e.g., 2023 NEC 220.83) can be entered in /HPXML/SoftwareInfo/extension/ElectricPanelCalculations/ServiceFeeders. If not entered, electric panel loads will not be calculated. These calculations are currently considered experimental research features.

Element	Type	Units	Constraints	Required	Default	Notes
Type	string		See [31]	Yes		Electric panel calculation vintage/method; multiple are allowed

[31]

Type choices are “2023 Existing Dwelling Load-Based” and “2023 Existing Dwelling Meter-Based”, and are described as follows:

- 2023 Existing Dwelling Load-Based: Using a load summing method based on Section 220.83 of the 2023 National Electrical Code.

- 2023 Existing Dwelling Meter-Based: Using a maximum demand method based on Section 220.87 of the 2023 National Electrical Code.

If running Whole SFA/MF Buildings with any “Dwelling Load-Based” calculation types, load calculations will be performed on each individual dwelling unit and then summed across units of the building. Running Whole SFA/MF Buildings with any “Dwelling Meter-Based” calculation types is not supported.

See Electric Panel Outputs for descriptions of how calculated loads appear in the output files.

The electric panel baseline peak power is entered in /HPXML/Building/BuildingDetails/BuildingSummary/extension.

Element	Type	Units	Constraints	Required	Default	Notes
ElectricPanelBaselinePeakPower	double	W	> 0	See [32]		Used for meter-based load calculations

[32]

ElectricPanelBaselinePeakPower only required if meter-based load calculations are desired.

HPXML Building

OpenStudio-HPXML can be used to model either individual residential Dwelling Units or Whole SFA/MF Buildings.

In either case, each residential dwelling unit is entered as a /HPXML/Building.

Element	Type	Units	Constraints	Required	Default	Notes
BuildingID	id			Yes		Unique identifier

Dwelling Units

OpenStudio-HPXML can model individual residential dwelling units – either a single-family detached (SFD) building, or a single unit of a single-family attached (SFA) or multifamily (MF) building. This approach:

• Is required/desired for certain applications (e.g., a Home Energy Score or an Energy Rating Index calculation).

• Improves runtime speed by being able to simulate individual units in parallel (as opposed to simulating the entire building).

For these simulations:

• Surfaces can be defined adjacent to generic SFA/MF spaces (e.g., “other housing unit” or “other multifamily buffer space”) with assumed temperature profiles (see HPXML Locations).

• Various building components (e.g., ducts, water heaters, appliances) can be located in these SFA/MF spaces.

• Shared systems (HVAC, water heating, mechanical ventilation, etc.) serving multiple dwelling units can be defined, in which these systems are approximated as individual systems with efficiency adjustments to estimate the energy use attributed to the unit.

• Energy use attributed only to the dwelling unit is calculated.

Whole SFA/MF Buildings

Alternatively, OpenStudio-HPXML can model whole SFA/MF buildings in a single combined simulation.

Modeling a whole SFA/MF building is defined in /HPXML/SoftwareInfo/extension.

Element	Type	Units	Constraints	Required	Default	Notes
WholeSFAorMFBuildingSimulation	boolean			No	false	Whether to run an individual dwelling unit or whole building for SFA/MF [33]

[33]

When WholeSFAorMFBuildingSimulation is false and the HPXML contains multiple Building elements, you must tell OpenStudio-HPXML which Building to run as described in the Basic Run usage instructions.

For these simulations:

• An HPXML file with multiple Building elements is used, where each Building represents an individual dwelling unit.

• Unit multipliers (using the NumberofUnits element; see HPXML Building Construction) can be specified to model unique dwelling units, rather than all dwelling units, reducing simulation runtime.

• Adjacent SFA/MF common spaces are still modeled using assumed temperature profiles, not as separate thermal zones. (This may change in the future.)

• Shared systems are still modeled as individual systems, not shared systems connected to multiple dwelling unit. (This may change in the future.)

• Energy use for the entire building is calculated; you cannot get energy use for individual dwelling units. (This may change in the future.)

Notes/caveats about this approach:

• Some inputs (e.g., EPW location or ground conductivity) cannot vary across Building elements.

• HPXML Batteries and HPXML Vehicles are not currently supported.

• HPXML Utility Bill Scenarios using detailed Electricity Rates are not supported.

HPXML Building Site

Building site information can be entered in /HPXML/Building/Site.

Element	Type	Units	Constraints	Required	Default	Notes
SiteID	id			Yes		Unique identifier
Address/CityMunicipality	string			No	See [34]	Address city/municipality
Address/StateCode	string			No	See [35]	Address state/territory
Address/ZipCode	string		See [36]	See [37]		Address ZIP Code
GeoLocation/Latitude	double	deg	>= -90, <= 90	No	See [38]	Site latitude (negative for southern hemisphere)
GeoLocation/Longitude	double	deg	>= -180, <= 180	No	See [39]	Site longitude (negative for western hemisphere)
Elevation	double	ft		No	See [40]	Site elevation
TimeZone/UTCOffset	double		>= -12, <= 14	No	See [41]	Difference in decimal hours between the home’s time zone and UTC
TimeZone/DSTObserved	boolean			No	true	Daylight saving time observed?

[34]

If CityMunicipality not provided, defaults according to the EPW weather file header.

[35]

If StateCode not provided, defaults according to the EPW weather file header.

[36]

ZipCode can be defined as the standard 5 number postal code, or it can have the additional 4 number code separated by a hyphen.

[37]

Either ZipCode or WeatherStation/extension/EPWFilePath (see HPXML Weather Station) must be provided.

[38]

If Latitude not provided, defaults according to the EPW weather file header.

[39]

If Longitude not provided, defaults according to the EPW weather file header.

[40]

If Elevation not provided, defaults according to the EPW weather file header.

[41]

If UTCOffset not provided, defaults according to the EPW weather file header.

If daylight saving time is observed, additional information can be specified in /HPXML/Building/Site/TimeZone/extension.

Element	Type	Units	Constraints	Required	Default	Notes
DSTBeginMonth and DSTBeginDayOfMonth	integer		>= 1, <= 12 and >= 1, <= 31	No	EPW else 3/12 (March 12) [42]	Start date
DSTEndMonth and DSTEndDayOfMonth	integer		>= 1, <= 12 and >= 1, <= 31	No	EPW else 11/5 (November 5)	End date

[42]

Daylight saving dates will be defined according to the EPW weather file header; if not available, fallback default values listed above will be used.

HPXML Building Summary

High-level building summary information is entered in /HPXML/Building/BuildingDetails/BuildingSummary.

HPXML Site

Site information is entered in /HPXML/Building/BuildingDetails/BuildingSummary/Site.

Element	Type	Units	Constraints	Required	Default	Notes
SiteType	string		See [43]	No	suburban	Terrain type for infiltration model
ShieldingofHome	string		See [44]	No	See [45]	Presence of nearby buildings, trees, obstructions for infiltration model
Soil/SoilType	string		See [46]	No	unknown	Soil type
Soil/MoistureType	string		See [47]	No	mixed	Soil moisture type
Soil/Conductivity	double	Btu/hr-ft-F	> 0	No	See [48]	Soil thermal conductivity
Soil/extension/Diffusivity	double	ft2/hr	> 0	No	See [49]	Soil thermal diffusivity
extension/Neighbors	element			No	<none>	Presence of neighboring buildings for solar shading

[43]

SiteType choices are “rural”, “suburban”, or “urban”.

[44]

ShieldingofHome choices are “normal”, “exposed”, or “well-shielded”.

[45]

If ShieldingofHome not provided, defaults to “normal” for single-family detached or manufactured home and “well-shielded” for single-family attached or apartment unit.

[46]

SoilType choices are “sand”, “silt”, “clay”, “loam”, “gravel”, or “unknown”.

[47]

MoistureType choices are “dry”, “wet”, or “mixed”.

[48]

If Conductivity not provided, defaults to Diffusivity / 0.0208 if Diffusivity provided, otherwise defaults based on SoilType and MoistureType per Table 1 of Ground Thermal Diffusivity Calculation by Direct Soil Temperature Measurement unless otherwise noted:

- unknown, dry/wet/mixed: 1.0000 (based on ANSI/RESNET/ICC 301-2022 Addendum C)

- sand/gravel, dry: 0.2311

- sand, wet: 1.3865

- sand, mixed: 0.8088

- silt/clay, dry: 0.2889

- silt/clay, wet: 0.9821

- silt/clay, mixed: 0.6355

- loam, dry/wet/mixed: 1.2132

- gravel, wet: 1.0399

- gravel, mixed: 0.6355

[49]

If Diffusivity not provided, defaults to Conductivity * 0.0208 if Conductivity provided, otherwise defaults based on SoilType and MoistureType per Table 1 of Ground Thermal Diffusivity Calculation by Direct Soil Temperature Measurement:

- unknown, dry/wet/mixed: 0.0208

- sand/gravel, dry: 0.0097

- sand, wet: 0.0322

- sand, mixed: 0.0210

- silt/clay, dry: 0.0120

- silt/clay, wet: 0.0194

- silt/clay, mixed: 0.0157

- loam, dry/wet/mixed: 0.0353

- gravel, wet: 0.0291

- gravel, mixed: 0.0194

Note

Soil conductivity is used for foundation heat transfer and ground source heat pumps. Soil diffusivity is used for ground source heat pumps.

HPXML Neighbor Buildings

For each neighboring building defined, additional information is entered in a extension/Neighbors/NeighborBuilding.

Element	Type	Units	Constraints	Required	Default	Notes
Azimuth or Orientation	integer or string	deg or direction	>= 0, <= 359 or See [50]	Yes		Direction of neighbors (clockwise from North)
Distance	double	ft	> 0	Yes		Distance of neighbor from the dwelling unit
Height	double	ft	> 0	No	See [51]	Height of neighbor

[50]

Orientation choices are “northeast”, “east”, “southeast”, “south”, “southwest”, “west”, “northwest”, or “north” The azimuth/orientation of the neighboring building must match the azimuth/orientation of at least one wall in the home, otherwise an error will be thrown.

[51]

If Height not provided, assumed to be same height as the dwelling unit.

HPXML Building Occupancy

Building occupancy is entered in /HPXML/Building/BuildingDetails/BuildingSummary/BuildingOccupancy.

Element	Type	Units	Constraints	Required	Default	Notes
NumberofResidents	double		>= 0	No	See [52]	Number of occupants
extension/WeekdayScheduleFractions	array			No	See [53]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [54]	12 comma-separated monthly multipliers
extension/GeneralWaterUseUsageMultiplier	double		>= 0	No	1.0	Multiplier on general water use internal gains [55]
extension/GeneralWaterUseWeekdayScheduleFractions	array			No	See [56]	24 comma-separated weekday fractions
extension/GeneralWaterUseWeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/GeneralWaterUseMonthlyScheduleMultipliers	array			No	See [57]	12 comma-separated monthly multipliers

[52]

If NumberofResidents not provided, an asset calculation is performed assuming standard occupancy, in which occupant-driven end uses (e.g., plug loads, appliances, hot water) are calculated based on NumberofBedrooms. If NumberofResidents is provided, an operational calculation is instead performed, in which some occupant-driven end uses, as described throughout the documentation, are adjusted using the following relationship from RECS 2020:

- manufactured home: NumberofBedrooms = -1.26 + 1.61 * NumberofResidents

- single-family detached: NumberofBedrooms = -2.19 + 2.08 * NumberofResidents

- single-family attached: NumberofBedrooms = -1.98 + 1.89 * NumberofResidents

- apartment unit: NumberofBedrooms = -1.36 + 1.49 * NumberofResidents

[53]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[54]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[55]

Sensible and latent internal gains from general water use (floor mopping, shower evaporation, water films on showers, tubs & sinks surfaces, plant watering, etc.), as defined by ANSI/RESNET/ICC 301-2019. If NumberofResidents provided, this will be adjusted using the above equations from RECS.

[56]

If GeneralWaterUseWeekdayScheduleFractions or GeneralWaterUseWeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[57]

If GeneralWaterUseMonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

HPXML Building Construction

Building construction is entered in /HPXML/Building/BuildingDetails/BuildingSummary/BuildingConstruction.

Element	Type	Units	Constraints	Required	Default	Notes
YearBuilt	integer		> 0	See [58]		Year built of the dwelling unit
ResidentialFacilityType	string		See [59]	Yes		Type of dwelling unit
UnitHeightAboveGrade	double	ft		No	See [60]	Height of the unit’s lowest conditioned floor above grade [61]
NumberofUnits	integer		>= 1	No	1	Unit multiplier [62]
NumberofConditionedFloors	double		> 0	Yes		Number of conditioned floors (including a conditioned basement; excluding a conditioned crawlspace)
NumberofConditionedFloorsAboveGrade	double		> 0, <= NumberofConditionedFloors	Yes		Number of conditioned floors above grade (including a walkout basement)
AverageCeilingHeight	double	ft	> 0	No	See [63]	Floor to ceiling height within conditioned space
NumberofBedrooms	integer		>= 0	Yes		Number of bedrooms
NumberofBathrooms	integer		> 0	No	See [64]	Number of bathrooms
ConditionedFloorArea	double	ft2	> 0	Yes		Floor area within conditioned space boundary (excluding conditioned crawlspace floor area)
ConditionedBuildingVolume	double	ft3	> 0	No	See [65]	Volume within conditioned space boundary (including a conditioned basement/crawlspace)

[58]

YearBuilt is required when Leakiness Description is the only air leakage type specified.

[59]

ResidentialFacilityType choices are “single-family detached”, “single-family attached”, “apartment unit”, or “manufactured home”.

[60]

If UnitHeightAboveGrade not provided, defaults to 2 ft if all HPXML Floors have ExteriorAdjacentTo with “outside”/”manufactured home underbelly”, the maximum foundation wall depth below grade (negative) if there’s a conditioned basement, and otherwise 0 ft.

[61]

UnitHeightAboveGrade is useful to characterize the height of apartment units above ground level or homes on pier and beam foundations. When greater than zero, it is used along with HPXML Air Infiltration to calculate the wind speed for the infiltration model.

[62]

NumberofUnits defines the number of similar dwelling units represented by the HPXML Building element. EnergyPlus simulation results will be multiplied by this value. For example, when modeling Whole SFA/MF Buildings, this allows modeling unique dwelling units, rather than all dwelling units, to reduce simulation runtime. Note that when NumberofUnits is greater than 1, a few capabilities are not currently supported:

- HPXML Dehumidifier

- Ground-to-Air Heat Pump

- On-Off Thermostat Deadband Temperature (see HPXML Simulation Control)

- Heat Pump Backup Capacity Increment (see HPXML Simulation Control)

[63]

If AverageCeilingHeight not provided, defaults to (ConditionedBuildingVolume - ConditionedCrawlspaceVolume) / ConditionedFloorArea if ConditionedBuildingVolume is provided. If ConditionedBuildingVolume not provided, AverageCeilingHeight defaults to 8.0 ft (unless there is a cathedral ceiling, in which case the value is adjusted).

[64]

If NumberofBathrooms not provided, calculated as NumberofBedrooms/2 + 0.5 based on the 2010 BAHSP.

[65]

If ConditionedBuildingVolume not provided, defaults to ConditionedFloorArea * AverageCeilingHeight + ConditionedCrawlspaceVolume.

HPXML Schedules

Schedules for a variety of building features can be defined using:

• Simple Schedule Inputs

• Detailed Schedule Inputs

• Default Schedules

It is allowed to use simple, detailed, and defaulted values in the same HPXML file.

Simple Schedule Inputs

Simple schedule inputs are available as weekday/weekend fractions and monthly multipliers for a variety of building characteristics. For example, see the WeekdayScheduleFractions, WeekendScheduleFractions, and MonthlyScheduleMultipliers inputs for HPXML Building Occupancy.

Detailed Schedule Inputs

Detailed schedule inputs allow schedule values for every hour or timestep of the simulation. They can be used to reflect real-world or stochastic occupancy.

Detailed schedule inputs are provided via one or more CSV file that should be referenced in the HPXML file as /HPXML/Building/BuildingDetails/BuildingSummary/extension/SchedulesFilePath elements. The column names available in the schedule CSV files are:

Column Name	Units	Notes	Can Be Stochastically Generated [66]
occupants	frac	Occupant heat gain schedule.	Yes
lighting_interior	frac	Interior lighting energy use schedule.	Yes
lighting_exterior	frac	Exterior lighting energy use schedule.	No
lighting_garage	frac	Garage lighting energy use schedule.	Yes
lighting_exterior_holiday	frac	Exterior holiday lighting energy use schedule.	No
cooking_range	frac	Cooking range & oven energy use schedule.	Yes
refrigerator	frac	Primary refrigerator energy use schedule.	No
extra_refrigerator	frac	Non-primary refrigerator energy use schedule.	No
freezer	frac	Freezer energy use schedule.	No
dishwasher	frac	Dishwasher energy use schedule.	Yes
clothes_washer	frac	Clothes washer energy use schedule.	Yes
clothes_dryer	frac	Clothes dryer energy use schedule.	Yes
ceiling_fan	frac	Ceiling fan energy use schedule.	Yes
plug_loads_other	frac	Other plug load energy use schedule.	Yes
plug_loads_tv	frac	Television plug load energy use schedule.	Yes
plug_loads_vehicle	frac	Electric vehicle plug load energy use schedule. [67]	No
plug_loads_well_pump	frac	Well pump plug load energy use schedule.	No
fuel_loads_grill	frac	Grill fuel load energy use schedule.	No
fuel_loads_lighting	frac	Lighting fuel load energy use schedule.	No
fuel_loads_fireplace	frac	Fireplace fuel load energy use schedule.	No
pool_pump	frac	Pool pump energy use schedule.	No
pool_heater	frac	Pool heater energy use schedule.	No
permanent_spa_pump	frac	Permanent spa pump energy use schedule.	No
permanent_spa_heater	frac	Permanent spa heater energy use schedule.	No
hot_water_dishwasher	frac	Dishwasher hot water use schedule.	Yes
hot_water_clothes_washer	frac	Clothes washer hot water use schedule.	Yes
hot_water_fixtures	frac	Fixtures (sinks, showers, baths) hot water use schedule.	Yes
hot_water_recirculation_pump	frac	Hot water recirculation pump schedule.	No
general_water_use	frac	General water use internal gains.	No
heating_setpoint	F	Thermostat heating setpoint schedule.	No
cooling_setpoint	F	Thermostat cooling setpoint schedule.	No
hvac_maximum_power_ratio	frac	Variable speed system maximum power ratio schedule. [68]	No
water_heater_setpoint	F	Water heater setpoint schedule.	No
water_heater_operating_mode	0/1	Heat pump water heater operating mode schedule. 0=hybrid/auto, 1=heat pump only.	No
battery	-1 to 1	Battery availability schedule. Positive for charging, negative for discharging.	No
electric_vehicle	-1 to 1	Electric vehicle schedule. Positive for charging, negative for discharging. [69]	Yes

[66]

A detailed stochastic occupancy schedule CSV file can also be automatically generated for these columns; see the Usage Instructions for the commands. The stochastic occupancy schedules are generated using the methodology described in Stochastic simulation of occupant-driven energy use in a bottom-up residential building stock model. Inputs for the stochastic schedule generator are entered in:

- /HPXML/Building/BuildingDetails/BuildingSummary/BuildingOccupancy/NumberofResidents

- /HPXML/Building/Site/Address/StateCode (optional)

- /HPXML/Building/Site/GeoLocation/Latitude (optional)

- /HPXML/Building/Site/GeoLocation/Longitude (optional)

- /HPXML/Building/Site/TimeZone/UTCOffset (optional)

See HPXML Building Occupancy and HPXML Building Site for more information.

[67]

For use with electric vehicles described using HPXML Plug Loads.

[68]

This feature is an advanced research capability. This schedule allows modeling shedding controls for variable speed HVAC systems (instead of setpoint changes) to limit the power of HVAC per AHRI 1380. While any fraction value can be entered, this is primarily intended to reflect the AHRI capabilities, which has two levels of load shed: “General Curtailment” and “Critical Curtailment”. A “General Curtailment” signal prevents the equipment from running at more than 70% of max power and “Critical Curtailment” limits it to 40% of max power until comfort constraints are violated (4F off the setpoint). During the shedding events, the main heat pump is limited to running below the specified fraction of rated power, and the backup system is locked out. When the comfort constraints are violated, both heat pump and backup systems are allowed to run at full load to recover the indoor temperature until reaching setpoint.

[69]

For use with electric vehicles described using HPXML Vehicles. This schedule represents times in which EV charging is available or EV discharging occurs. If a vehicle is fully charged during a scheduled charging event, there will be no charging load. If a vehicle battery is fully depleted during a discharging event, there will be no further discharging energy and the vehicle will accumulate unmet EV driving hours (see Annual Unmet Hours).

Columns with units of frac must be normalized to MAX=1; that is, these schedules only define when energy is used, not how much energy is used. In other words, the amount of energy or hot water used in each simulation timestep is essentially the schedule value divided by the sum of all schedule values in the column, multiplied by the annual energy or hot water use. Example schedule CSV files are provided in the HPXMLtoOpenStudio/resources/schedule_files directory.

The schedule file must have a full year of data even if the simulation is not an entire year. Frequency of schedule values do not need to match the simulation timestep. For example, hourly schedules can be used with a 10-minute simulation timestep, or 10-minute schedules can be used with an hourly simulation timestep.

Warning

For simulations with daylight saving enabled (which is the default), EnergyPlus will skip forward an hour in the CSV on the “spring forward” day and repeat an hour on the “fall back” day.

Default Schedules

If neither simple nor detailed inputs are provided, then schedules are defaulted. Default schedules are typically smooth, averaged schedules. These default schedules (and data sources) are described in the table below (e.g., see “occupants” rows for the default occupant heat gain schedule). They can also be found at HPXMLtoOpenStudio/resources/data/default_schedules.csv.

Schedule Name	Element	Values	Data Source
occupants	WeekdayScheduleFractions	0.035, 0.035, 0.035, 0.035, 0.035, 0.059, 0.082, 0.055, 0.027, 0.014, 0.014, 0.014, 0.014, 0.014, 0.019, 0.027, 0.041, 0.055, 0.068, 0.082, 0.082, 0.070, 0.053, 0.035	Table C.3(5) of ANSI/RESNET/ICC 301-2022 Addendum C
occupants	WeekendScheduleFractions	0.035, 0.035, 0.035, 0.035, 0.035, 0.059, 0.082, 0.055, 0.027, 0.014, 0.014, 0.014, 0.014, 0.014, 0.019, 0.027, 0.041, 0.055, 0.068, 0.082, 0.082, 0.070, 0.053, 0.035	Table C.3(5) of ANSI/RESNET/ICC 301-2022 Addendum C
occupants	MonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
general_water_use	GeneralWaterUseWeekdayScheduleFractions	0.023, 0.021, 0.021, 0.025, 0.027, 0.038, 0.044, 0.039, 0.037, 0.037, 0.034, 0.035, 0.035, 0.035, 0.039, 0.043, 0.051, 0.064, 0.065, 0.072, 0.073, 0.063, 0.045, 0.034	Table C.3(5) of ANSI/RESNET/ICC 301-2022 Addendum C
general_water_use	GeneralWaterUseWeekendScheduleFractions	0.023, 0.021, 0.021, 0.025, 0.027, 0.038, 0.044, 0.039, 0.037, 0.037, 0.034, 0.035, 0.035, 0.035, 0.039, 0.043, 0.051, 0.064, 0.065, 0.072, 0.073, 0.063, 0.045, 0.034	Table C.3(5) of ANSI/RESNET/ICC 301-2022 Addendum C
general_water_use	GeneralWaterUseMonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
lighting_interior	InteriorWeekdayScheduleFractions	0.012, 0.010, 0.010, 0.010, 0.011, 0.018, 0.030, 0.038, 0.041, 0.041, 0.039, 0.037, 0.036, 0.035, 0.037, 0.041, 0.050, 0.065, 0.086, 0.106, 0.110, 0.079, 0.040, 0.018	Table C.3(3) of ANSI/RESNET/ICC 301-2022 Addendum C
lighting_interior	InteriorWeekendScheduleFractions	0.012, 0.010, 0.010, 0.010, 0.011, 0.018, 0.030, 0.038, 0.041, 0.041, 0.039, 0.037, 0.036, 0.035, 0.037, 0.041, 0.050, 0.065, 0.086, 0.106, 0.110, 0.079, 0.040, 0.018	Table C.3(3) of ANSI/RESNET/ICC 301-2022 Addendum C
lighting_interior	InteriorMonthlyScheduleMultipliers	1.19, 1.11, 1.02, 0.93, 0.84, 0.80, 0.82, 0.88, 0.98, 1.07, 1.16, 1.20	Table C.3(4) of ANSI/RESNET/ICC 301-2022 Addendum C
lighting_exterior	ExteriorWeekdayScheduleFractions	0.040, 0.037, 0.037, 0.035, 0.035, 0.039, 0.044, 0.041, 0.031, 0.025, 0.024, 0.024, 0.025, 0.028, 0.030, 0.035, 0.044, 0.056, 0.064, 0.068, 0.070, 0.065, 0.056, 0.047	Table C.3(3) of ANSI/RESNET/ICC 301-2022 Addendum C
lighting_exterior	ExteriorWeekendScheduleFractions	0.040, 0.037, 0.037, 0.035, 0.035, 0.039, 0.044, 0.041, 0.031, 0.025, 0.024, 0.024, 0.025, 0.028, 0.030, 0.035, 0.044, 0.056, 0.064, 0.068, 0.070, 0.065, 0.056, 0.047	Table C.3(3) of ANSI/RESNET/ICC 301-2022 Addendum C
lighting_exterior	ExteriorMonthlyScheduleMultipliers	1.19, 1.11, 1.02, 0.93, 0.84, 0.80, 0.82, 0.88, 0.98, 1.07, 1.16, 1.20	Table C.3(4) of ANSI/RESNET/ICC 301-2022 Addendum C
lighting_garage	GarageWeekdayScheduleFractions	0.023, 0.019, 0.015, 0.017, 0.021, 0.031, 0.042, 0.041, 0.034, 0.029, 0.027, 0.025, 0.021, 0.021, 0.021, 0.026, 0.031, 0.044, 0.084, 0.117, 0.113, 0.096, 0.063, 0.039	Table C.3(3) of ANSI/RESNET/ICC 301-2022 Addendum C
lighting_garage	GarageWeekendScheduleFractions	0.023, 0.019, 0.015, 0.017, 0.021, 0.031, 0.042, 0.041, 0.034, 0.029, 0.027, 0.025, 0.021, 0.021, 0.021, 0.026, 0.031, 0.044, 0.084, 0.117, 0.113, 0.096, 0.063, 0.039	Table C.3(3) of ANSI/RESNET/ICC 301-2022 Addendum C
lighting_garage	GarageMonthlyScheduleMultipliers	1.19, 1.11, 1.02, 0.93, 0.84, 0.80, 0.82, 0.88, 0.98, 1.07, 1.16, 1.20	Table C.3(4) of ANSI/RESNET/ICC 301-2022 Addendum C
lighting_exterior_holiday	WeekdayScheduleFractions	0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.008, 0.098, 0.168, 0.194, 0.284, 0.192, 0.037, 0.019
lighting_exterior_holiday	WeekendScheduleFractions	0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.008, 0.098, 0.168, 0.194, 0.284, 0.192, 0.037, 0.019
cooking_range	WeekdayScheduleFractions	0.008, 0.008, 0.008, 0.008, 0.008, 0.015, 0.023, 0.039, 0.046, 0.046, 0.046, 0.054, 0.062, 0.046, 0.039, 0.054, 0.076, 0.134, 0.114, 0.058, 0.039, 0.031, 0.023, 0.015	Table C.3(1) of ANSI/RESNET/ICC 301-2022 Addendum C
cooking_range	WeekendScheduleFractions	0.008, 0.008, 0.008, 0.008, 0.008, 0.015, 0.023, 0.039, 0.046, 0.046, 0.046, 0.054, 0.062, 0.046, 0.039, 0.054, 0.076, 0.134, 0.114, 0.058, 0.039, 0.031, 0.023, 0.015	Table C.3(1) of ANSI/RESNET/ICC 301-2022 Addendum C
cooking_range	MonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
refrigerator	WeekdayScheduleFractions	0.040, 0.039, 0.038, 0.037, 0.036, 0.036, 0.038, 0.040, 0.041, 0.041, 0.040, 0.040, 0.042, 0.042, 0.042, 0.041, 0.044, 0.048, 0.050, 0.048, 0.047, 0.046, 0.044, 0.041	Figure 16 of the 2010 BAHSP
refrigerator	WeekendScheduleFractions	0.040, 0.039, 0.038, 0.037, 0.036, 0.036, 0.038, 0.040, 0.041, 0.041, 0.040, 0.040, 0.042, 0.042, 0.042, 0.041, 0.044, 0.048, 0.050, 0.048, 0.047, 0.046, 0.044, 0.041	Figure 16 of the 2010 BAHSP
refrigerator	MonthlyScheduleMultipliers	0.837, 0.835, 1.084, 1.084, 1.084, 1.096, 1.096, 1.096, 1.096, 0.931, 0.925, 0.837	Figure 24 of the 2010 BAHSP
refrigerator	ConstantScheduleCoefficients	-0.487, -0.340, -0.370, -0.361, -0.515, -0.684, -0.471, -0.159, -0.079, -0.417, -0.411, -0.386, -0.240, -0.314, -0.160, -0.121, -0.469, -0.412, -0.091, 0.077, -0.118, -0.247, -0.445, -0.544	Table C.3(2) of ANSI/RESNET/ICC 301-2022 Addendum C
refrigerator	TemperatureScheduleCoefficients	0.019, 0.016, 0.017, 0.016, 0.018, 0.021, 0.019, 0.015, 0.015, 0.019, 0.018, 0.018, 0.016, 0.017, 0.015, 0.015, 0.020, 0.020, 0.017, 0.014, 0.016, 0.017, 0.019, 0.020	Table C.3(2) of ANSI/RESNET/ICC 301-2022 Addendum C
extra_refrigerator	WeekdayScheduleFractions	0.040, 0.039, 0.038, 0.037, 0.036, 0.036, 0.038, 0.040, 0.041, 0.041, 0.040, 0.040, 0.042, 0.042, 0.042, 0.041, 0.044, 0.048, 0.050, 0.048, 0.047, 0.046, 0.044, 0.041	Figure 16 of the 2010 BAHSP
extra_refrigerator	WeekendScheduleFractions	0.040, 0.039, 0.038, 0.037, 0.036, 0.036, 0.038, 0.040, 0.041, 0.041, 0.040, 0.040, 0.042, 0.042, 0.042, 0.041, 0.044, 0.048, 0.050, 0.048, 0.047, 0.046, 0.044, 0.041	Figure 16 of the 2010 BAHSP
extra_refrigerator	MonthlyScheduleMultipliers	0.837, 0.835, 1.084, 1.084, 1.084, 1.096, 1.096, 1.096, 1.096, 0.931, 0.925, 0.837	Figure 24 of the 2010 BAHSP
extra_refrigerator	ConstantScheduleCoefficients	-0.487, -0.340, -0.370, -0.361, -0.515, -0.684, -0.471, -0.159, -0.079, -0.417, -0.411, -0.386, -0.240, -0.314, -0.160, -0.121, -0.469, -0.412, -0.091, -0.077, -0.118, -0.247, -0.445, -0.544	Table C.3(2) of ANSI/RESNET/ICC 301-2022 Addendum C
extra_refrigerator	TemperatureScheduleCoefficients	0.019, 0.016, 0.017, 0.016, 0.018, 0.021, 0.019, 0.015, 0.015, 0.019, 0.018, 0.018, 0.016, 0.017, 0.015, 0.015, 0.020, 0.020, 0.017, 0.014, 0.016, 0.017, 0.019, 0.020	Table C.3(2) of ANSI/RESNET/ICC 301-2022 Addendum C
freezer	WeekdayScheduleFractions	0.040, 0.039, 0.038, 0.037, 0.036, 0.036, 0.038, 0.040, 0.041, 0.041, 0.040, 0.040, 0.042, 0.042, 0.042, 0.041, 0.044, 0.048, 0.050, 0.048, 0.047, 0.046, 0.044, 0.041	Figure 16 of the 2010 BAHSP
freezer	WeekendScheduleFractions	0.040, 0.039, 0.038, 0.037, 0.036, 0.036, 0.038, 0.040, 0.041, 0.041, 0.040, 0.040, 0.042, 0.042, 0.042, 0.041, 0.044, 0.048, 0.050, 0.048, 0.047, 0.046, 0.044, 0.041	Figure 16 of the 2010 BAHSP
freezer	MonthlyScheduleMultipliers	0.837, 0.835, 1.084, 1.084, 1.084, 1.096, 1.096, 1.096, 1.096, 0.931, 0.925, 0.837	Figure 24 of the 2010 BAHSP
dishwasher	WeekdayScheduleFractions	0.015, 0.007, 0.005, 0.003, 0.003, 0.010, 0.020, 0.031, 0.058, 0.065, 0.056, 0.048, 0.042, 0.046, 0.036, 0.038, 0.038, 0.049, 0.087, 0.111, 0.090, 0.067, 0.044, 0.031	Table C.3(1) of ANSI/RESNET/ICC 301-2022 Addendum C
dishwasher	WeekendScheduleFractions	0.015, 0.007, 0.005, 0.003, 0.003, 0.010, 0.020, 0.031, 0.058, 0.065, 0.056, 0.048, 0.042, 0.046, 0.036, 0.038, 0.038, 0.049, 0.087, 0.111, 0.090, 0.067, 0.044, 0.031	Table C.3(1) of ANSI/RESNET/ICC 301-2022 Addendum C
dishwasher	MonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
clothes_washer	WeekdayScheduleFractions	0.009, 0.007, 0.004, 0.004, 0.007, 0.011, 0.022, 0.049, 0.073, 0.086, 0.084, 0.075, 0.067, 0.060, 0.049, 0.051, 0.050, 0.049, 0.049, 0.049, 0.049, 0.047, 0.032, 0.017	Table C.3(1) of ANSI/RESNET/ICC 301-2022 Addendum C
clothes_washer	WeekendScheduleFractions	0.009, 0.007, 0.004, 0.004, 0.007, 0.011, 0.022, 0.049, 0.073, 0.086, 0.084, 0.075, 0.067, 0.060, 0.049, 0.051, 0.050, 0.049, 0.049, 0.049, 0.049, 0.047, 0.032, 0.017	Table C.3(1) of ANSI/RESNET/ICC 301-2022 Addendum C
clothes_washer	MonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
clothes_dryer	WeekdayScheduleFractions	0.010, 0.006, 0.004, 0.002, 0.004, 0.006, 0.016, 0.032, 0.048, 0.068, 0.078, 0.081, 0.074, 0.067, 0.058, 0.061, 0.055, 0.054, 0.051, 0.051, 0.052, 0.054, 0.044, 0.024	Table C.3(1) of ANSI/RESNET/ICC 301-2022 Addendum C
clothes_dryer	WeekendScheduleFractions	0.010, 0.006, 0.004, 0.002, 0.004, 0.006, 0.016, 0.032, 0.048, 0.068, 0.078, 0.081, 0.074, 0.067, 0.058, 0.061, 0.055, 0.054, 0.051, 0.051, 0.052, 0.054, 0.044, 0.024	Table C.3(1) of ANSI/RESNET/ICC 301-2022 Addendum C
clothes_dryer	MonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
ceiling_fan	WeekdayScheduleFractions	0.057, 0.057, 0.057, 0.057, 0.057, 0.057, 0.057, 0.024, 0.024, 0.024, 0.024, 0.024, 0.024, 0.024, 0.024, 0.024, 0.024, 0.024, 0.052, 0.057, 0.057, 0.057, 0.057, 0.057	Table C.3(5) of ANSI/RESNET/ICC 301-2022 Addendum C
ceiling_fan	WeekendScheduleFractions	0.057, 0.057, 0.057, 0.057, 0.057, 0.057, 0.057, 0.024, 0.024, 0.024, 0.024, 0.024, 0.024, 0.024, 0.024, 0.024, 0.024, 0.024, 0.052, 0.057, 0.057, 0.057, 0.057, 0.057	Table C.3(5) of ANSI/RESNET/ICC 301-2022 Addendum C
plug_loads_other	WeekdayScheduleFractions	0.036, 0.036, 0.036, 0.036, 0.036, 0.036, 0.038, 0.041, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.044, 0.047, 0.050, 0.051, 0.050, 0.048, 0.044, 0.040, 0.037	Table C.3(1) of ANSI/RESNET/ICC 301-2022 Addendum C
plug_loads_other	WeekendScheduleFractions	0.036, 0.036, 0.036, 0.036, 0.036, 0.036, 0.038, 0.041, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.044, 0.047, 0.050, 0.051, 0.050, 0.048, 0.044, 0.040, 0.037	Table C.3(1) of ANSI/RESNET/ICC 301-2022 Addendum C
plug_loads_other	MonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
plug_loads_vehicle	WeekdayScheduleFractions	0.053, 0.042, 0.034, 0.027, 0.026, 0.022, 0.017, 0.014, 0.012, 0.011, 0.011, 0.013, 0.018, 0.022, 0.026, 0.037, 0.054, 0.074, 0.088, 0.089, 0.086, 0.083, 0.076, 0.065
plug_loads_vehicle	WeekendScheduleFractions	0.055, 0.045, 0.036, 0.03, 0.028, 0.024, 0.019, 0.016, 0.014, 0.013, 0.014, 0.016, 0.021, 0.028, 0.035, 0.044, 0.056, 0.069, 0.077, 0.08, 0.078, 0.073, 0.067, 0.06
plug_loads_vehicle	MonthlyScheduleMultipliers	1.128, 1.1, 1.037, 0.984, 0.948, 0.932, 0.931, 0.93, 0.932, 0.969, 1.017, 1.096
plug_loads_tv	WeekdayScheduleFractions	0.014, 0.007, 0.004, 0.003, 0.004, 0.006, 0.010, 0.015, 0.020, 0.025, 0.028, 0.031, 0.033, 0.038, 0.042, 0.046, 0.054, 0.062, 0.080, 0.110, 0.132, 0.125, 0.077, 0.034	Table C.3(1) of ANSI/RESNET/ICC 301-2022 Addendum C
plug_loads_tv	WeekendScheduleFractions	0.014, 0.007, 0.004, 0.003, 0.004, 0.006, 0.010, 0.015, 0.020, 0.025, 0.028, 0.031, 0.033, 0.038, 0.042, 0.046, 0.054, 0.062, 0.080, 0.110, 0.132, 0.125, 0.077, 0.034	Table C.3(1) of ANSI/RESNET/ICC 301-2022 Addendum C
plug_loads_tv	MonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
plug_loads_well_pump	WeekdayScheduleFractions	0.044, 0.023, 0.019, 0.015, 0.016, 0.018, 0.026, 0.033, 0.033, 0.032, 0.033, 0.033, 0.032, 0.032, 0.032, 0.033, 0.045, 0.057, 0.066, 0.076, 0.081, 0.086, 0.075, 0.065	Figure 23 of the 2010 BAHSP
plug_loads_well_pump	WeekendScheduleFractions	0.044, 0.023, 0.019, 0.015, 0.016, 0.018, 0.026, 0.033, 0.033, 0.032, 0.033, 0.033, 0.032, 0.032, 0.032, 0.033, 0.045, 0.057, 0.066, 0.076, 0.081, 0.086, 0.075, 0.065	Figure 23 of the 2010 BAHSP
plug_loads_well_pump	MonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
fuel_loads_grill	WeekdayScheduleFractions	0.004, 0.001, 0.001, 0.002, 0.007, 0.012, 0.029, 0.046, 0.044, 0.041, 0.044, 0.046, 0.042, 0.038, 0.049, 0.059, 0.110, 0.161, 0.115, 0.070, 0.044, 0.019, 0.013, 0.007	Figure 23 of the 2010 BAHSP
fuel_loads_grill	WeekendScheduleFractions	0.004, 0.001, 0.001, 0.002, 0.007, 0.012, 0.029, 0.046, 0.044, 0.041, 0.044, 0.046, 0.042, 0.038, 0.049, 0.059, 0.110, 0.161, 0.115, 0.070, 0.044, 0.019, 0.013, 0.007	Figure 23 of the 2010 BAHSP
fuel_loads_grill	MonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
fuel_loads_lighting	WeekdayScheduleFractions	0.044, 0.023, 0.019, 0.015, 0.016, 0.018, 0.026, 0.033, 0.033, 0.032, 0.033, 0.033, 0.032, 0.032, 0.032, 0.033, 0.045, 0.057, 0.066, 0.076, 0.081, 0.086, 0.075, 0.065	Figure 23 of the 2010 BAHSP
fuel_loads_lighting	WeekendScheduleFractions	0.044, 0.023, 0.019, 0.015, 0.016, 0.018, 0.026, 0.033, 0.033, 0.032, 0.033, 0.033, 0.032, 0.032, 0.032, 0.033, 0.045, 0.057, 0.066, 0.076, 0.081, 0.086, 0.075, 0.065	Figure 23 of the 2010 BAHSP
fuel_loads_lighting	MonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
fuel_loads_fireplace	WeekdayScheduleFractions	0.044, 0.023, 0.019, 0.015, 0.016, 0.018, 0.026, 0.033, 0.033, 0.032, 0.033, 0.033, 0.032, 0.032, 0.032, 0.033, 0.045, 0.057, 0.066, 0.076, 0.081, 0.086, 0.075, 0.065	Figure 23 of the 2010 BAHSP
fuel_loads_fireplace	WeekendScheduleFractions	0.044, 0.023, 0.019, 0.015, 0.016, 0.018, 0.026, 0.033, 0.033, 0.032, 0.033, 0.033, 0.032, 0.032, 0.032, 0.033, 0.045, 0.057, 0.066, 0.076, 0.081, 0.086, 0.075, 0.065	Figure 23 of the 2010 BAHSP
fuel_loads_fireplace	MonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
pool_pump	WeekdayScheduleFractions	0.003, 0.003, 0.003, 0.004, 0.008, 0.015, 0.026, 0.044, 0.084, 0.121, 0.127, 0.121, 0.120, 0.090, 0.075, 0.061, 0.037, 0.023, 0.013, 0.008, 0.004, 0.003, 0.003, 0.003	Figure 23 of the 2010 BAHSP
pool_pump	WeekendScheduleFractions	0.003, 0.003, 0.003, 0.004, 0.008, 0.015, 0.026, 0.044, 0.084, 0.121, 0.127, 0.121, 0.120, 0.090, 0.075, 0.061, 0.037, 0.023, 0.013, 0.008, 0.004, 0.003, 0.003, 0.003	Figure 23 of the 2010 BAHSP
pool_pump	MonthlyScheduleMultipliers	1.154, 1.161, 1.013, 1.010, 1.013, 0.888, 0.883, 0.883, 0.888, 0.978, 0.974, 1.154	Figure 24 of the 2010 BAHSP
pool_heater	WeekdayScheduleFractions	0.003, 0.003, 0.003, 0.004, 0.008, 0.015, 0.026, 0.044, 0.084, 0.121, 0.127, 0.121, 0.120, 0.090, 0.075, 0.061, 0.037, 0.023, 0.013, 0.008, 0.004, 0.003, 0.003, 0.003	Figure 23 of the 2010 BAHSP
pool_heater	WeekendScheduleFractions	0.003, 0.003, 0.003, 0.004, 0.008, 0.015, 0.026, 0.044, 0.084, 0.121, 0.127, 0.121, 0.120, 0.090, 0.075, 0.061, 0.037, 0.023, 0.013, 0.008, 0.004, 0.003, 0.003, 0.003	Figure 23 of the 2010 BAHSP
pool_heater	MonthlyScheduleMultipliers	1.154, 1.161, 1.013, 1.010, 1.013, 0.888, 0.883, 0.883, 0.888, 0.978, 0.974, 1.154	Figure 24 of the 2010 BAHSP
permanent_spa_pump	WeekdayScheduleFractions	0.024, 0.029, 0.024, 0.029, 0.047, 0.067, 0.057, 0.024, 0.024, 0.019, 0.015, 0.014, 0.014, 0.014, 0.024, 0.058, 0.126, 0.122, 0.068, 0.061, 0.051, 0.043, 0.024, 0.024	Figure 23 of the 2010 BAHSP
permanent_spa_pump	WeekendScheduleFractions	0.024, 0.029, 0.024, 0.029, 0.047, 0.067, 0.057, 0.024, 0.024, 0.019, 0.015, 0.014, 0.014, 0.014, 0.024, 0.058, 0.126, 0.122, 0.068, 0.061, 0.051, 0.043, 0.024, 0.024	Figure 23 of the 2010 BAHSP
permanent_spa_pump	MonthlyScheduleMultipliers	0.921, 0.928, 0.921, 0.915, 0.921, 1.160, 1.158, 1.158, 1.160, 0.921, 0.915, 0.921	Figure 24 of the 2010 BAHSP
permanent_spa_heater	WeekdayScheduleFractions	0.024, 0.029, 0.024, 0.029, 0.047, 0.067, 0.057, 0.024, 0.024, 0.019, 0.015, 0.014, 0.014, 0.014, 0.024, 0.058, 0.126, 0.122, 0.068, 0.061, 0.051, 0.043, 0.024, 0.024	Figure 23 of the 2010 BAHSP
permanent_spa_heater	WeekendScheduleFractions	0.024, 0.029, 0.024, 0.029, 0.047, 0.067, 0.057, 0.024, 0.024, 0.019, 0.015, 0.014, 0.014, 0.014, 0.024, 0.058, 0.126, 0.122, 0.068, 0.061, 0.051, 0.043, 0.024, 0.024	Figure 23 of the 2010 BAHSP
permanent_spa_heater	MonthlyScheduleMultipliers	0.837, 0.835, 1.084, 1.084, 1.084, 1.096, 1.096, 1.096, 1.096, 0.931, 0.925, 0.837	Figure 24 of the 2010 BAHSP
hot_water_fixtures	WaterFixturesWeekdayScheduleFractions	0.012, 0.006, 0.004, 0.005, 0.010, 0.034, 0.078, 0.086, 0.080, 0.067, 0.056, 0.047, 0.040, 0.035, 0.033, 0.031, 0.038, 0.051, 0.060, 0.060, 0.055, 0.048, 0.038, 0.026	Table C.3(5) of ANSI/RESNET/ICC 301-2022 Addendum C
hot_water_fixtures	WaterFixturesWeekendScheduleFractions	0.012, 0.006, 0.004, 0.005, 0.010, 0.034, 0.078, 0.086, 0.080, 0.067, 0.056, 0.047, 0.040, 0.035, 0.033, 0.031, 0.038, 0.051, 0.060, 0.060, 0.055, 0.048, 0.038, 0.026	Table C.3(5) of ANSI/RESNET/ICC 301-2022 Addendum C
hot_water_fixtures	WaterFixturesMonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
hot_water_recirculation_pump_no_control	RecirculationPumpWeekdayScheduleFractions	0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042	Equation 4.2-43a of ANSI/RESNET/ICC 301-2022 Addendum C
hot_water_recirculation_pump_no_control	RecirculationPumpWeekendScheduleFractions	0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042, 0.042	Equation 4.2-43a of ANSI/RESNET/ICC 301-2022 Addendum C
hot_water_recirculation_pump_demand_control	RecirculationPumpWeekdayScheduleFractions	0.012, 0.006, 0.004, 0.005, 0.010, 0.034, 0.078, 0.086, 0.080, 0.067, 0.056, 0.047, 0.040, 0.035, 0.033, 0.031, 0.038, 0.051, 0.060, 0.060, 0.055, 0.048, 0.038, 0.026	Table C.3(5) of ANSI/RESNET/ICC 301-2022 Addendum C
hot_water_recirculation_pump_demand_control	RecirculationPumpWeekendScheduleFractions	0.012, 0.006, 0.004, 0.005, 0.010, 0.034, 0.078, 0.086, 0.080, 0.067, 0.056, 0.047, 0.040, 0.035, 0.033, 0.031, 0.038, 0.051, 0.060, 0.060, 0.055, 0.048, 0.038, 0.026	Table C.3(5) of ANSI/RESNET/ICC 301-2022 Addendum C
hot_water_recirculation_pump_temperature_control	RecirculationPumpWeekdayScheduleFractions	0.067, 0.072, 0.074, 0.073, 0.069, 0.048, 0.011, 0.003, 0.009, 0.020, 0.030, 0.037, 0.043, 0.047, 0.050, 0.051, 0.044, 0.034, 0.026, 0.026, 0.030, 0.036, 0.045, 0.055	Table C.3(5) of ANSI/RESNET/ICC 301-2022 Addendum C
hot_water_recirculation_pump_temperature_control	RecirculationPumpWeekendScheduleFractions	0.067, 0.072, 0.074, 0.073, 0.069, 0.048, 0.011, 0.003, 0.009, 0.020, 0.030, 0.037, 0.043, 0.047, 0.050, 0.051, 0.044, 0.034, 0.026, 0.026, 0.030, 0.036, 0.045, 0.055	Table C.3(5) of ANSI/RESNET/ICC 301-2022 Addendum C
hot_water_recirculation_pump	RecirculationPumpMonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
electric_vehicle	WeekdayScheduleFractions	0.0714, 0.0714, 0.0714, 0.0714, 0.0714, 0.0714, 0.0714, -0.3535, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, -0.3221, -0.3244, 0.0714, 0.0714, 0.0714, 0.0714, 0.0714, 0.0714, 0.0714
electric_vehicle	WeekendScheduleFractions	0.0588, 0.0588, 0.0588, 0.0588, 0.0588, 0.0588, 0.0588, 0.0588, 0.0588, -0.3334, 0, 0, 0, 0, -0.3293, -0.3372, 0.0588, 0.0588, 0.0588, 0.0588, 0.0588, 0.0588, 0.0588, 0.0588
electric_vehicle	MonthlyScheduleMultipliers	1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0

HPXML HVAC Sizing Control

HVAC equipment sizing controls are entered in /HPXML/Building/BuildingDetails/BuildingSummary/extension/HVACSizingControl. Additional autosizing factor inputs are available at the system level, see HPXML Heating Systems, HPXML Cooling Systems and HPXML Heat Pumps.

Element	Type	Units	Constraints	Required	Default	Notes
HeatPumpSizingMethodology	string		See [70]	No	HERS	Logic for autosized heat pumps
HeatPumpBackupSizingMethodology	string		See [71]	No	emergency	Logic for autosized heat pump backup
AllowIncreasedFixedCapacities	boolean			No	false	Logic for fixed capacity HVAC equipment [72]

[70]

HeatPumpSizingMethodology choices are ‘ACCA’, ‘HERS’, or ‘MaxLoad’, and are described as follows:

- ACCA: autosized heat pumps have their nominal capacity sized per ACCA Manual J/S based on cooling design loads, with some oversizing allowances for larger heating design loads.

- HERS: same as ACCA except autosized heat pumps have their nominal capacity sized equal to at least the larger of heating and sensible cooling design loads.

- MaxLoad: autosized heat pumps have their nominal capacity sized based on the larger of heating/cooling design loads, while taking into account the heat pump’s reduced capacity at the design temperature, such that no backup heating should be necessary.

[71]

HeatPumpBackupSizingMethodology choices are ‘emergency’ or ‘supplemental’, and are described as follows:

- emergency: heat pump backup capacity will be autosized to meet the ACCA Manual J heating design load.

- supplemental: heat pump backup capacity will be autosized to meet the remainder of the ACCA Manual J heating design load not met by the heat pump at the heating design temperature.

Heat pump backup capacity is often sized for emergency heat so that it can meet the entire design load if the heat pump fails. Some contractors/homeowners may choose not to do so, perhaps due to insufficient panel/wiring capacity. Note: If the minimum temperature for the heat pump’s compressor (i.e., CompressorLockoutTemperature or BackupHeatingSwitchoverTemperature) is above the heating design temperature, the two sizing methodologies will give identical results.

[72]

If AllowIncreasedFixedCapacities is true, the larger of user-specified fixed capacity and design load will be used (to reduce potential for unmet loads); otherwise user-specified fixed capacity is used.

Manual J Inputs

Additional inputs for ACCA Manual J design loads, used for sizing HVAC equipment, can be entered in /HPXML/Building/BuildingDetails/BuildingSummary/extension/HVACSizingControl/ManualJInputs.

Element	Type	Units	Constraints	Required	Default	Notes
HeatingDesignTemperature	double	F		No	See [73]	Heating outdoor design temperature
CoolingDesignTemperature	double	F		No	See [74]	Cooling outdoor design temperature
DailyTemperatureRange	string		See [75]	No	See [76]	Class based on average difference between daily high/low outdoor temperatures during the hottest month
HeatingSetpoint	double	F		No	70	Conditioned space heating setpoint [77]
CoolingSetpoint	double	F		No	75	Conditioned space cooling setpoint [78]
HumiditySetpoint	double	frac	> 0, < 1	No	See [79]	Conditioned space relative humidity
HumidityDifference	double	grains		No	See [80]	Difference between absolute humidity of the outdoor/indoor air during the summer
InternalLoadsSensible	double	Btu/hr	>= 0	No	See [81]	Sensible internal loads for cooling design load
InternalLoadsLatent	double	Btu/hr	>= 0	No	0	Latent internal loads for cooling design load
NumberofOccupants	double		>= 0	No	See [82]	Number of occupants for cooling design load
InfiltrationShieldingClass	integer		>= 1, <= 5	No	See [83]	Wind shielding class for infiltration design loads
InfiltrationMethod	string		See [84]	No	See [85]	Method to calculate infiltration design loads

[73]

If HeatingDesignTemperature not provided, the 99% heating design temperature is obtained from the DESIGN CONDITIONS header section inside the EPW weather file. If not available in the EPW header, it is calculated from the 8760 hourly temperatures in the EPW.

[74]

If CoolingDesignTemperature not provided, the 1% cooling design temperature is obtained from the DESIGN CONDITIONS header section inside the EPW weather file. If not available in the EPW header, it is calculated from the 8760 hourly temperatures in the EPW.

[75]

DailyTemperatureRange choices are “low”, “medium”, or “high”.

[76]

If DailyTemperatureRange not provided, the cooling drybulb temperature range is obtained from the DESIGN CONDITIONS header section inside the EPW weather file. If not available in the EPW header, it is calculated from the 8760 hourly temperatures in the EPW.

[77]

Any heating setpoint other than 70F is not in compliance with Manual J.

[78]

Any cooling setpoint other than 75F is not in compliance with Manual J.

[79]

If HumiditySetpoint not provided, defaults to 0.45 in a dry climate, otherwise 0.5.

[80]

If HumidityDifference not provided, it is calculated from the other inputs/defaults and the cooling humidity ratio. The cooling humidity ratio is calculated from the DESIGN CONDITIONS header section inside the EPW weather file or, if not available, the 8760 hourly temperatures in the EPW.

[81]

If InternalLoadsSensible not provided, defaults to the sum of conditioned spaces’ InternalLoadsSensible values if provided (see HPXML Zones/Spaces). Otherwise defaults to 2400 Btu/hr if there is one refrigerator and no freezer, or 3600 Btu/hr if two refrigerators or a freezer. This default represents loads that normally occur during the early evening in mid-summer. Additional adjustments or custom internal loads can instead be specified here.

[82]

If NumberofOccupants not provided, defaults to the sum of conditioned spaces’ NumberofOccupants values if provided (see HPXML Zones/Spaces). Otherwise defaults to the the larger of NumberofBedrooms+1 and NumberofResidents (if provided). Each occupant produces an additional 230 Btu/hr sensible load and 200 Btu/hr latent load.

[83]

If InfiltrationShieldingClass not provided defaults to class 4 with these adjustments: +1 if ShieldingofHome=”well-shielded”, -1 if ShieldingofHome=”exposed”, +1 if SiteType=”urban”, -1 if SiteType=”rural”.

[84]

InfiltrationMethod choices are “default infiltration table” or “blower door”.

[85]

If InfiltrationMethod not provided, defaults based on the current inputs in HPXML. If Leakiness Description is the only air leakage type specified, defaults to “default infiltration table”; otherwise defaults to “blower door”.

HPXML Shading Control

Shading controls for window and skylight summer/winter shading coefficients are entered in /HPXML/Building/BuildingDetails/BuildingSummary/extension/ShadingControl. If not provided, summer will be default based on the cooling season defined in the 2010 BAHSP, using monthly average temperatures. The remainder of the year is winter.

Element	Type	Units	Constraints	Required	Default	Notes
SummerBeginMonth	integer		>= 1, <= 12	Yes		Summer shading start date
SummerBeginDayOfMonth	integer		>= 1, <= 31	Yes		Summer shading start date
SummerEndMonth	integer		>= 1, <= 12	Yes		Summer shading end date
SummerEndDayOfMonth	integer		>= 1, <= 31	Yes		Summer shading end date

HPXML Zones/Spaces

Conditioned zones can be provided to produce HVAC Zone Design Loads and HVAC Space Design Loads.

Note

The specification of conditioned zones does not currently affect the energy simulation as all conditioned space in a dwelling unit is currently modeled as a single EnergyPlus conditioned thermal zone. If multiple conditioned zones are specified, the HVAC systems attached to a given zone are assumed to fully condition it for the HVAC design load calculations.

One or more zones can be entered as a /HPXML/Building/BuildingDetails/Zones/Zone.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
ZoneType	string		See [86]	Yes		Type of zone
Spaces/Space	element			Yes		One or more spaces within the zone

[86]

ZoneType choices are “unconditioned” or “conditioned”.

Each space within a conditioned zone can be entered as a /HPXML/Building/BuildingDetails/Zones/Zone[ZoneType="conditioned"]/Spaces/Space.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
FloorArea	double	ft2	> 0	Yes		Space floor area
extension/ManualJInputs/InternalLoadsSensible	double	Btu/hr	>= 0	No [87]	See [88]	Conditioned space sensible internal loads for cooling design load
extension/ManualJInputs/InternalLoadsLatent	double	Btu/hr	>= 0	No [89]	See [90]	Conditioned space latent internal loads for cooling design load
extension/ManualJInputs/NumberofOccupants	double		>= 0	No [91]	See [92]	Conditioned space number of occupants for cooling design load
extension/ManualJInputs/FenestrationLoadProcedure	string		See [93]	No	standard	Conditioned space fenestration load procedure [94]

[87]

InternalLoadsSensible must be provided for all spaces or no spaces.

[88]

If InternalLoadsSensible not provided for a conditioned space, the home’s total internal sensible loads are apportioned to each space by floor area.

[89]

InternalLoadsLatent must be provided for all spaces or no spaces.

[90]

If InternalLoadsLatent not provided for a conditioned space, the home’s total internal latent loads are apportioned to each space by floor area.

[91]

NumberofOccupants must be provided for all spaces or no spaces.

[92]

If NumberofOccupants not provided for a conditioned space, the home’s total number of occupants are apportioned to each space by floor area.

[93]

FenestrationLoadProcedure choices are “standard” or “peak”.

[94]

The “standard” choice should be used for cooling individual rooms and spaces with a single-zone, central air system, where the local fenestration load equals the daily average fenestration load for the room/space plus the AED (Adequate Exposure Diversity) excursion value for the room/space. The “peak” choice should be used for room and space cooling by any time of multi-zone system or local unitary equipment (in which the HVAC system has the ability to adjust cooling capacity on a room or zone basis), where the local fenestration load equals the peak value on the AED curve. Consult ACCA Manual J for more information.

HPXML Climate Zones

HPXML Climate Zone IECC

Climate zone information can be optionally entered as an /HPXML/Building/BuildingDetails/ClimateandRiskZones/ClimateZoneIECC.

Element	Type	Units	Constraints	Required	Default	Notes
Year	integer		See [95]	Yes		IECC year
ClimateZone	string		See [96]	Yes		IECC zone

[95]

Year choices are 2003, 2006, 2009, 2012, 2015, 2018, 2021, or 2024.

[96]

ClimateZone choices are “1A”, “1B”, “1C”, “2A”, “2B”, “2C”, “3A”, “3B”, “3C”, “4A”, “4B”, “4C”, “5A”, “5B”, “5C”, “6A”, “6B”, “6C”, “7”, or “8”.

If Climate zone information not provided, defaults according to the mapping found at HPXMLtoOpenStudio/resources/data/zipcode_weather_stations.csv.

HPXML Weather Station

Weather information is entered in /HPXML/Building/BuildingDetails/ClimateandRiskZones/WeatherStation.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Name	string			Yes		Name of weather station
extension/EPWFilePath	string			See [97]	See [98]	Path to the EnergyPlus weather file (EPW) [99]

[97]

Either EPWFilePath or Address/ZipCode (see HPXML Building Site) must be provided.

[98]

If EPWFilePath not provided, defaults based on the U.S. TMY3 weather station closest to the zip code centroid. The mapping can be found at HPXMLtoOpenStudio/resources/data/zipcode_weather_stations.csv.

[99]

The full set of U.S. TMY3 EPW weather files can be downloaded here.

HPXML Enclosure

The dwelling unit’s enclosure is entered in /HPXML/Building/BuildingDetails/Enclosure.

All surfaces that bound different space types of the dwelling unit (i.e., not just thermal boundary surfaces) must be specified in the HPXML file. For example, an attached garage would generally be defined by walls adjacent to conditioned space, walls adjacent to outdoors, a slab, and a roof or ceiling. For software tools that do not collect sufficient inputs for every required surface, the software developers will need to make assumptions about these surfaces or collect additional input.

Interior partition surfaces (e.g., walls between rooms inside conditioned space, or the floor between two conditioned stories) can be excluded.

For single-family attached (SFA) or multifamily (MF) buildings, surfaces between unconditioned space and the neighboring unit’s same unconditioned space should set InteriorAdjacentTo and ExteriorAdjacentTo to the same value. For example, a foundation wall between the unit’s vented crawlspace and the neighboring unit’s vented crawlspace would use InteriorAdjacentTo="crawlspace - vented" and ExteriorAdjacentTo="crawlspace - vented".

Warning

It is the software tool’s responsibility to provide the appropriate building surfaces. While some error-checking is in place, it is not possible to know whether some surfaces are incorrectly missing.

Also note that wall and roof surfaces do not require an azimuth/orientation to be specified. Rather, only the windows/skylights themselves require an azimuth/orientation. Thus, software tools can choose to use a single wall (or roof) surface to represent multiple wall (or roof) surfaces for the entire building if all their other properties (construction type, interior/exterior adjacency, etc.) are identical.

HPXML Air Infiltration

Building air leakage is entered in /HPXML/Building/BuildingDetails/Enclosure/AirInfiltration/AirInfiltrationMeasurement.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
TypeOfInfiltrationLeakage	string		See [100]	See [101]		Type of infiltration leakage
InfiltrationVolume	double	ft3	> 0	No	See [102]	Volume associated with infiltration measurement [103]
InfiltrationHeight	double	ft	> 0	No	See [104]	Height associated with infiltration measurement [105]
extension/Aext	double	frac	> 0	No	See [106]	Exterior area ratio for SFA/MF dwelling units

[100]

TypeOfInfiltrationLeakage choices are “unit total” or “unit exterior only”, and are described as follows:

- unit total: the provided infiltration value represents the total infiltration to the dwelling unit, as measured by a compartmentalization test, in which case it will be adjusted by extension/Aext.

- unit exterior only: the provided infiltration value represents the infiltration to the dwelling unit from outside only, as measured by a guarded test.

[101]

TypeOfInfiltrationLeakage required if single-family attached or apartment unit.

[102]

If InfiltrationVolume not provided, it is estimated from other inputs (e.g., ConditionedBuildingVolume, attics/foundations with WithinInfiltrationVolume=true, etc.).

[103]

InfiltrationVolume can be thought of as the volume of space most impacted by a blower door test. Note that InfiltrationVolume can be larger than ConditionedBuildingVolume as it can include, e.g., attics or basements with access doors/hatches that are open during the blower door test.

[104]

If InfiltrationHeight not provided, it is estimated from other inputs (e.g., ConditionedFloorArea, NumberofConditionedFloorsAboveGrade, attics/foundations with WithinInfiltrationVolume=true, etc.).

[105]

InfiltrationHeight is defined as the vertical distance between the lowest and highest above-grade points within the pressure boundary, per ASHRAE 62.2. It is used along with the UnitHeightAboveGrade in HPXML Building Construction to calculate the wind speed for the infiltration model.

[106]

If Aext not provided and TypeOfInfiltrationLeakage is “unit total”, defaults for single-family attached and apartment units to the ratio of exterior (adjacent to outside) envelope surface area to total (adjacent to outside, other dwelling units, or other MF spaces) envelope surface area, as defined by ANSI/RESNET/ICC 301-2019 and ASHRAE 62.2-2019. Note that all attached surfaces, even adiabatic surfaces, must be defined in the HPXML file. If single-family detached or TypeOfInfiltrationLeakage is “unit exterior only”, Aext is 1.

In addition, one of the following air leakage types must also be defined:

• ACH or CFM

• Natural ACH or CFM

• Effective Leakage Area

• Leakiness Description

Note

Infiltration airflow rates are calculated using the Alberta Air Infiltration Model (AIM-2) (also known as the ASHRAE Enhanced model). When there is a flue or chimney present (see Flue or Chimney) with combustion air from conditioned space, higher infiltration airflow rates are modeled because the flue leakage is at a different height for stack effect.

ACH or CFM

If entering air leakage as ACH or CFM at a user-specific pressure, additional information is entered in /HPXML/Building/BuildingDetails/Enclosure/AirInfiltration/AirInfiltrationMeasurement. For example, ACH50 (ACH at 50 Pascals) is a commonly obtained value from a blower door measurement.

Element	Type	Units	Constraints	Required	Default	Notes
HousePressure	double	Pa	> 0	Yes		House pressure with respect to outside [107]
BuildingAirLeakage/UnitofMeasure	string		See [108]	Yes		Units for air leakage
BuildingAirLeakage/AirLeakage	double		> 0	Yes		Value for air leakage

[107]

HousePressure typical value is 50 Pa.

[108]

UnitofMeasure choices are “ACH” or “CFM”.

Natural ACH or CFM

If entering air leakage as natural ACH or CFM, additional information is entered in /HPXML/Building/BuildingDetails/Enclosure/AirInfiltration/AirInfiltrationMeasurement. Natural ACH or CFM represents the annual average infiltration that a building will see.

Element	Type	Units	Constraints	Required	Default	Notes
BuildingAirLeakage/UnitofMeasure	string		See [109]	Yes		Units for air leakage
BuildingAirLeakage/AirLeakage	double		> 0	Yes		Value for air leakage

[109]

UnitofMeasure choices are “ACHnatural” or “CFMnatural”.

Effective Leakage Area

If entering air leakage as Effective Leakage Area (ELA), additional information is entered in /HPXML/Building/BuildingDetails/Enclosure/AirInfiltration/AirInfiltrationMeasurement. Effective Leakage Area is defined as the area of a special nozzle-shaped hole (similar to the inlet of a blower door fan) that would leak the same amount of air as the building does at a pressure difference of 4 Pascals. Note that ELA is different than Equivalent Leakage Area (EqLA), which involves a sharp-edged hole at a pressure difference of 10 Pascals.

Element	Type	Units	Constraints	Required	Default	Notes
EffectiveLeakageArea	double	sq. in.	>= 0	Yes		Effective leakage area value

Leakiness Description

If entering air leakage using the Leakiness Description, additional information is entered in /HPXML/Building/BuildingDetails/Enclosure/AirInfiltration/AirInfiltrationMeasurement.

Element	Type	Units	Constraints	Required	Default	Notes
LeakinessDescription	string		See [110]	Yes		Qualitative description of leakiness [111]

[110]

LeakinessDescription choices are “very tight”, “tight”, “average”, “leaky” or “very leaky”.

[111]

For energy modeling, average air leakage is estimated via a regression developed by LBNL using ResDB data (https://resdb.lbl.gov) that takes into account IECC climate zone, conditioned floor area, year built, foundation type, duct location, etc. The leakiness description is then used to further adjust the default (average) infiltration rate using leakage multipliers derived from ACCA Manual J Table 5A. HPXML inputs map to Manual J Table 5A inputs as follows:

- “very tight” => “Tight”

- “tight” => “Semi-Tight”

- “average” => “Average”

- “leaky” => “Semi-Loose”

- “very leaky” => “Loose”

Flue or Chimney

The presence of a flue or chimney with combustion air from conditioned space can be entered in /HPXML/Building/BuildingDetails/Enclosure/AirInfiltration.

Element	Type	Units	Constraints	Required	Default	Notes
extension/HasFlueOrChimneyInConditionedSpace	boolean			No	See [112]	Flue or chimney with combustion air from conditioned space

[112]

If HasFlueOrChimneyInConditionedSpace not provided, defaults to true if any of the following conditions are met, otherwise false:

- heating system is non-electric Furnace, Boiler, WallFurnace, FloorFurnace, Stove, or SpaceHeater located in conditioned space and AFUE/Percent is less than 0.89,

- heating system is non-electric Fireplace located in conditioned space, or

- water heater is non-electric with energy factor (or equivalent calculated from uniform energy factor) less than 0.63 and located in conditioned space.

HPXML Attics

If the dwelling unit has an unvented attic, additional information is entered in /HPXML/Building/BuildingDetails/Enclosure/Attics/Attic[AtticType/Attic[Vented="false"]].

Element	Type	Units	Constraints	Required	Default	Notes
WithinInfiltrationVolume	boolean		See [113]	No	false	Whether door/hatch to conditioned space open during blower door test [114]

[113]

If there are multiple unvented attics, they must all have the same value.

[114]

See ANSI/RESNET/ICC 380-2022 for more information.

If the dwelling unit has a vented attic, additional information is entered in /HPXML/Building/BuildingDetails/Enclosure/Attics/Attic[AtticType/Attic[Vented="true"]]/VentilationRate.

Element	Type	Units	Constraints	Required	Default	Notes
UnitofMeasure	string		See [115]	No	SLA	Units for ventilation rate
Value	double		> 0 [116]	No	1/300 [117]	Value for ventilation rate

[115]

UnitofMeasure choices are “SLA” (specific leakage area) or “ACHnatural” (natural air changes per hour).

[116]

If there are multiple vented attics, they must all have the same value.

[117]

Value default based on ANSI/RESNET/ICC 301-2019.

HPXML Foundations

If the dwelling unit has a conditioned basement, additional information is entered in /HPXML/Building/BuildingDetails/Enclosure/Foundations/Foundation/FoundationType/Basement[Conditioned='true'].

Element	Type	Units	Constraints	Required	Default	Notes
WithinInfiltrationVolume	boolean		See [118]	No	true	Whether door/hatch to conditioned space open during blower door test [119]

[118]

If there are multiple conditioned basements, they must all have the same value.

[119]

See ANSI/RESNET/ICC 380-2022 for more information.

If the dwelling unit has an unconditioned basement, additional information is entered in /HPXML/Building/BuildingDetails/Enclosure/Foundations/Foundation/FoundationType/Basement[Conditioned='false'].

Element	Type	Units	Constraints	Required	Default	Notes
WithinInfiltrationVolume	boolean		See [120]	No	false	Whether door/hatch to conditioned space open during blower door test [121]

[120]

If there are multiple unconditioned basements, they must all have the same value.

[121]

See ANSI/RESNET/ICC 380-2022 for more information.

If the dwelling unit has an unvented crawlspace, additional information is entered in /HPXML/Building/BuildingDetails/Enclosure/Foundations/Foundation/FoundationType/Crawlspace[Vented='false'].

Element	Type	Units	Constraints	Required	Default	Notes
WithinInfiltrationVolume	boolean		See [122]	No	false	Whether door/hatch to conditioned space open during blower door test [123]

[122]

If there are multiple unvented crawlspaces, they must all have the same value.

[123]

See ANSI/RESNET/ICC 380-2022 for more information.

If the dwelling unit has a vented crawlspace, additional information is entered in /HPXML/Building/BuildingDetails/Enclosure/Foundations/Foundation[FoundationType/Crawlspace[Vented="true"]]/VentilationRate.

Element	Type	Units	Constraints	Required	Default	Notes
UnitofMeasure	string		See [124]	No	SLA	Units for ventilation rate
Value	double		> 0 [125]	No	1/150 [126]	Value for ventilation rate

[124]

UnitofMeasure only choice is “SLA” (specific leakage area).

[125]

If there are multiple vented crawlspaces, they must all have the same value.

[126]

Value default based on ANSI/RESNET/ICC 301-2019.

If the dwelling unit has a conditioned crawlspace, additional information is entered in /HPXML/Building/BuildingDetails/Enclosure/Foundations/Foundation/FoundationType/Crawlspace[Conditioned='true'].

Element	Type	Units	Constraints	Required	Default	Notes
WithinInfiltrationVolume	boolean		See [127]	No	true	Whether door/hatch to conditioned space open during blower door test [128]

[127]

If there are multiple conditioned crawlspaces, they must all have the same value.

[128]

See ANSI/RESNET/ICC 380-2022 for more information.

If the dwelling has a manufactured home belly-and-wing foundation, additional information is entered in /HPXML/Building/BuildingDetails/Enclosure/Foundations/Foundation/FoundationType/BellyAndWing.

Element	Type	Units	Constraints	Required	Default	Notes
SkirtPresent	boolean		See [129]	No	true	Presence of skirt [130]

[129]

If there are multiple manufactured home belly-and-wing foundations, they must all have the same value.

[130]

When a skirt is present, it is assumed that the foundation does not have exposure to wind.

HPXML Roofs

Each pitched or flat roof surface that is exposed to ambient conditions is entered as a /HPXML/Building/BuildingDetails/Enclosure/Roofs/Roof.

For a multifamily building where the dwelling unit has another dwelling unit above it, the surface between the two dwelling units should be considered a Floor and not a Roof.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToSpace	idref		See [131]	See [132]		ID of attached space
InteriorAdjacentTo	string		See [133]	Yes		Interior adjacent space type
Area	double	ft2	> 0	Yes		Gross area (including skylights)
Azimuth or Orientation	integer or string	deg or direction	>= 0, <= 359 or See [134]	No	See [135]	Direction (clockwise from North)
RoofType	string		See [136]	No	asphalt or fiberglass shingles	Roof type
RoofColor or SolarAbsorptance	string or double		See [137] or >= 0, <= 1	No	medium	Roof color or solar absorptance of outermost material [138]
Emittance	double		>= 0, <= 1	No	0.90	Emittance of outermost material
InteriorFinish/Type	string		See [139]	No	See [140]	Interior finish material
InteriorFinish/Thickness	double	in	>= 0	No	0.5	Interior finish thickness
Pitch	double	?/12	>= 0	Yes		Pitch [141]
RadiantBarrier	boolean			No	false	Presence of radiant barrier [142]
RadiantBarrierGrade	integer		>= 1, <= 3	No	1	Radiant barrier installation grade
Insulation/SystemIdentifier	id			Yes		Unique identifier
Insulation/AssemblyEffectiveRValue	double	F-ft2-hr/Btu	> 0	Yes		Assembly R-value [143]

[131]

If AttachedToSpace provided, it must reference a Space (within a conditioned Zone).

[132]

AttachedToSpace only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces) and the surface is adjacent to conditioned space.

[133]

InteriorAdjacentTo choices are “attic - vented”, “attic - unvented”, “conditioned space”, or “garage”. See HPXML Locations for descriptions.

[134]

Orientation choices are “northeast”, “east”, “southeast”, “south”, “southwest”, “west”, “northwest”, or “north”

[135]

If neither Azimuth nor Orientation provided, and it’s a pitched roof, modeled as four surfaces of equal area facing every direction. Azimuth/Orientation is irrelevant for flat roofs.

[136]

RoofType choices are “asphalt or fiberglass shingles”, “wood shingles or shakes”, “shingles”, “slate or tile shingles”, “metal surfacing”, “plastic/rubber/synthetic sheeting”, “expanded polystyrene sheathing”, “concrete”, or “cool roof”.

[137]

RoofColor choices are “light”, “medium”, “medium dark”, “dark”, or “reflective”.

[138]

If SolarAbsorptance not provided, defaults based on RoofType and RoofColor:

- asphalt or fiberglass shingles: dark=0.92, medium dark=0.89, medium=0.85, light=0.75, reflective=0.50

- wood shingles or shakes: dark=0.92, medium dark=0.89, medium=0.85, light=0.75, reflective=0.50

- shingles: dark=0.92, medium dark=0.89, medium=0.85, light=0.75, reflective=0.50

- slate or tile shingles: dark=0.90, medium dark=0.83, medium=0.75, light=0.60, reflective=0.30

- metal surfacing: dark=0.90, medium dark=0.83, medium=0.75, light=0.60, reflective=0.30

- plastic/rubber/synthetic sheeting: dark=0.90, medium dark=0.83, medium=0.75, light=0.60, reflective=0.30

- expanded polystyrene sheathing: dark=0.92, medium dark=0.89, medium=0.85, light=0.75, reflective=0.50

- concrete: dark=0.90, medium dark=0.83, medium=0.75, light=0.65, reflective=0.50

- cool roof: 0.30

[139]

InteriorFinish/Type choices are “gypsum board”, “gypsum composite board”, “plaster”, “wood”, “other”, or “none”.

[140]

InteriorFinish/Type defaults to “gypsum board” if InteriorAdjacentTo is conditioned space, otherwise “none”.

[141]

Pitch is entered as vertical rise in inches for every 12 inches of horizontal run. For example, 6.0 means a 6/12 roof, which has a 26.57-degree roof slope.

[142]

RadiantBarrier intended for attic roofs. Model assumes an emittance of 0.05.

[143]

AssemblyEffectiveRValue includes all material layers and interior/exterior air films. It should also include the effects of insulation gaps (installation grading) and/or compressed insulation in cavities per ANSI/RESNET/ICC 301-2022.

HPXML Rim Joists

Each rim joist surface (i.e., the perimeter of floor joists typically found between stories of a building or on top of a foundation wall) is entered as a /HPXML/Building/BuildingDetails/Enclosure/RimJoists/RimJoist.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToSpace	idref		See [144]	See [145]		ID of attached space
ExteriorAdjacentTo	string		See [146]	Yes		Exterior adjacent space type
InteriorAdjacentTo	string		See [147]	Yes		Interior adjacent space type
Area	double	ft2	> 0	Yes		Gross area
Azimuth or Orientation	integer or string	deg or direction	>= 0, <= 359 or See [148]	No	See [149]	Direction (clockwise from North)
Siding	string		See [150]	No	wood siding	Siding material
Color or SolarAbsorptance	string or double		See [151] or >= 0, <= 1	No	medium	Color or solar absorptance of outermost material [152]
Emittance	double		>= 0, <= 1	No	0.90	Emittance of outermost material
Insulation/SystemIdentifier	id			Yes		Unique identifier
Insulation/AssemblyEffectiveRValue	double	F-ft2-hr/Btu	> 0	Yes		Assembly R-value [153]

[144]

If AttachedToSpace provided, it must reference a Space (within a conditioned Zone).

[145]

AttachedToSpace only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces) and the surface is adjacent to conditioned space (and not adiabatic).

[146]

ExteriorAdjacentTo choices are “outside”, “attic - vented”, “attic - unvented”, “basement - conditioned”, “basement - unconditioned”, “crawlspace - vented”, “crawlspace - unvented”, “crawlspace - conditioned”, “garage”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[147]

InteriorAdjacentTo choices are “conditioned space”, “attic - vented”, “attic - unvented”, “basement - conditioned”, “basement - unconditioned”, “crawlspace - vented”, “crawlspace - unvented”, “crawlspace - conditioned”, or “garage”. See HPXML Locations for descriptions.

[148]

Orientation choices are “northeast”, “east”, “southeast”, “south”, “southwest”, “west”, “northwest”, or “north”

[149]

If neither Azimuth nor Orientation provided, and it’s an exterior rim joist, modeled as four surfaces of equal area facing every direction. Azimuth/Orientation is irrelevant for interior rim joists.

[150]

Siding choices are “wood siding”, “vinyl siding”, “stucco”, “fiber cement siding”, “brick veneer”, “aluminum siding”, “masonite siding”, “composite shingle siding”, “asbestos siding”, “synthetic stucco”, or “none”.

[151]

Color choices are “light”, “medium”, “medium dark”, “dark”, or “reflective”.

[152]

If SolarAbsorptance not provided, defaults based on Color:

- dark: 0.95

- medium dark: 0.85

- medium: 0.70

- light: 0.50

- reflective: 0.30

[153]

AssemblyEffectiveRValue includes all material layers and interior/exterior air films. It should also include the effects of insulation gaps (installation grading) and/or compressed insulation in cavities per ANSI/RESNET/ICC 301-2022.

HPXML Walls

Each wall surface is entered as a /HPXML/Building/BuildingDetails/Enclosure/Walls/Wall.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToSpace	idref		See [154]	See [155]		ID of attached space
ExteriorAdjacentTo	string		See [156]	Yes		Exterior adjacent space type
InteriorAdjacentTo	string		See [157]	Yes		Interior adjacent space type
WallType	element		See [158]	Yes		Wall type (for thermal mass)
Area	double	ft2	> 0	Yes		Gross area (including doors/windows)
Azimuth or Orientation	integer or string	deg or direction	>= 0, <= 359 or See [159]	No	See [160]	Direction (clockwise from North)
Siding	string		See [161]	No	wood siding	Siding material
Color or SolarAbsorptance	string or double		See [162] or >= 0, <= 1	No	medium	Color or solar absorptance of outermost material [163]
Emittance	double		>= 0, <= 1	No	0.90	Emittance of outermost material
InteriorFinish/Type	string		See [164]	No	See [165]	Interior finish material
InteriorFinish/Thickness	double	in	>= 0	No	0.5	Interior finish thickness
RadiantBarrier	boolean			No	false	Presence of radiant barrier [166]
RadiantBarrierGrade	integer		>= 1, <= 3	No	1	Radiant barrier installation grade
Insulation/SystemIdentifier	id			Yes		Unique identifier
Insulation/AssemblyEffectiveRValue	double	F-ft2-hr/Btu	> 0	Yes		Assembly R-value [167]

[154]

If AttachedToSpace provided, it must reference a Space (within a conditioned Zone).

[155]

AttachedToSpace only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces) and the surface is adjacent to conditioned space (and not adiabatic).

[156]

ExteriorAdjacentTo choices are “outside”, “attic - vented”, “attic - unvented”, “basement - conditioned”, “basement - unconditioned”, “crawlspace - vented”, “crawlspace - unvented”, “crawlspace - conditioned”, “garage”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[157]

InteriorAdjacentTo choices are “conditioned space”, “attic - vented”, “attic - unvented”, “basement - conditioned”, “basement - unconditioned”, “crawlspace - vented”, “crawlspace - unvented”, “crawlspace - conditioned”, or “garage”. See HPXML Locations for descriptions.

[158]

WallType child element choices are WoodStud, DoubleWoodStud, ConcreteMasonryUnit, StructuralInsulatedPanel, InsulatedConcreteForms, SteelFrame, SolidConcrete, StructuralBrick, StrawBale, Stone, LogWall, or Adobe.

[159]

Orientation choices are “northeast”, “east”, “southeast”, “south”, “southwest”, “west”, “northwest”, or “north”

[160]

If neither Azimuth nor Orientation provided, and it’s an exterior wall, modeled as four surfaces of equal area facing every direction. Azimuth/Orientation is irrelevant for interior walls (e.g., between conditioned space and garage).

[161]

Siding choices are “wood siding”, “vinyl siding”, “stucco”, “fiber cement siding”, “brick veneer”, “aluminum siding”, “masonite siding”, “composite shingle siding”, “asbestos siding”, “synthetic stucco”, or “none”.

[162]

Color choices are “light”, “medium”, “medium dark”, “dark”, or “reflective”.

[163]

If SolarAbsorptance not provided, defaults based on Color:

- dark: 0.95

- medium dark: 0.85

- medium: 0.70

- light: 0.50

- reflective: 0.30

[164]

InteriorFinish/Type choices are “gypsum board”, “gypsum composite board”, “plaster”, “wood”, “other”, or “none”.

[165]

InteriorFinish/Type defaults to “gypsum board” if InteriorAdjacentTo is conditioned space or basement - conditioned, otherwise “none”.

[166]

RadiantBarrier intended for attic gable walls. Model assumes an emittance of 0.05.

[167]

AssemblyEffectiveRValue includes all material layers and interior/exterior air films. It should also include the effects of insulation gaps (installation grading) and/or compressed insulation in cavities per ANSI/RESNET/ICC 301-2022.

HPXML Foundation Walls

Each foundation wall surface is entered as a /HPXML/Building/BuildingDetails/Enclosure/FoundationWalls/FoundationWall. Any wall surface in contact with the ground is considered a foundation wall.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToSpace	idref		See [168]	See [169]		ID of attached space
ExteriorAdjacentTo	string		See [170]	Yes		Exterior adjacent space type [171]
InteriorAdjacentTo	string		See [172]	Yes		Interior adjacent space type
Type	string		See [173]	No	solid concrete	Type of material
Height	double	ft	> 0	Yes		Total height
Area or Length	double	ft2 or ft	> 0	Yes		Gross area (including doors/windows) or length
Azimuth or Orientation	integer or string	deg or direction	>= 0, <= 359 or See [174]	No	See [175]	Direction (clockwise from North)
Thickness	double	in	> 0	No	8.0	Thickness excluding interior framing
DepthBelowGrade	double	ft	>= 0, <= Height	Yes		Depth below grade [176]
InteriorFinish/Type	string		See [177]	No	See [178]	Interior finish material
InteriorFinish/Thickness	double	in	>= 0	No	0.5	Interior finish thickness
Insulation/SystemIdentifier	id			Yes		Unique identifier
Insulation/Layer[InstallationType="continuous - interior"]	element			See [179]		Interior insulation layer
Insulation/Layer[InstallationType="continuous - exterior"]	element			See [180]		Exterior insulation layer
Insulation/AssemblyEffectiveRValue	double	F-ft2-hr/Btu	> 0	See [181]		Assembly R-value [182]

[168]

If AttachedToSpace provided, it must reference a Space (within a conditioned Zone).

[169]

AttachedToSpace only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces) and the surface is adjacent to conditioned space (and not adiabatic).

[170]

ExteriorAdjacentTo choices are “ground”, “basement - conditioned”, “basement - unconditioned”, “crawlspace - vented”, “crawlspace - unvented”, “crawlspace - conditioned”, “garage”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[171]

InteriorAdjacentTo choices are “basement - conditioned”, “basement - unconditioned”, “crawlspace - vented”, “crawlspace - unvented”, “crawlspace - conditioned”, or “garage”. See HPXML Locations for descriptions.

[172]

Interior foundation walls (e.g., between basement and crawlspace) should not use “ground” even if the foundation wall has some contact with the ground due to the difference in below-grade depths of the two adjacent spaces.

[173]

Type choices are “solid concrete”, “concrete block”, “concrete block foam core”, “concrete block vermiculite core”, “concrete block perlite core”, “concrete block solid core”, “double brick”, or “wood”.

[174]

Orientation choices are “northeast”, “east”, “southeast”, “south”, “southwest”, “west”, “northwest”, or “north”

[175]

If neither Azimuth nor Orientation provided, and it’s an exterior foundation wall, modeled as four surfaces of equal area facing every direction. Azimuth/Orientation is irrelevant for interior foundation walls (e.g., between basement and garage).

[176]

For exterior foundation walls, depth below grade is relative to the ground plane. For interior foundation walls, depth below grade is the vertical span of foundation wall in contact with the ground. For example, an interior foundation wall between an 8 ft conditioned basement and a 3 ft crawlspace has a height of 8 ft and a depth below grade of 5 ft. Alternatively, an interior foundation wall between an 8 ft conditioned basement and an 8 ft unconditioned basement has a height of 8 ft and a depth below grade of 0 ft.

[177]

InteriorFinish/Type choices are “gypsum board”, “gypsum composite board”, “plaster”, “wood”, “other”, or “none”.

[178]

InteriorFinish/Type defaults to “gypsum board” if InteriorAdjacentTo is basement - conditioned, otherwise “none”.

[179]

Layer[InstallationType=”continuous - interior”] only required if AssemblyEffectiveRValue is not provided.

[180]

Layer[InstallationType=”continuous - exterior”] only required if AssemblyEffectiveRValue is not provided.

[181]

AssemblyEffectiveRValue only required if Layer elements are not provided.

[182]

AssemblyEffectiveRValue includes all material layers and the interior air film; it should not include the exterior air film (for any above-grade exposure) or any soil thermal resistance. It should also include the effects of insulation gaps (installation grading) and/or compressed insulation in cavities per ANSI/RESNET/ICC 301-2022.

If insulation layers are provided, additional information is entered in each FoundationWall/Insulation/Layer.

Element	Type	Units	Constraints	Required	Default	Notes
NominalRValue	double	F-ft2-hr/Btu	>= 0	Yes		R-value of the foundation wall insulation; use zero if no insulation
DistanceToTopOfInsulation	double	ft	>= 0	No	0	Vertical distance from top of foundation wall to top of insulation
DistanceToBottomOfInsulation	double	ft	See [183]	No	Height	Vertical distance from top of foundation wall to bottom of insulation

[183]

When NominalRValue is non-zero, DistanceToBottomOfInsulation must be greater than DistanceToTopOfInsulation and less than or equal to FoundationWall/Height.

HPXML Floors

Each floor/ceiling surface that is not in contact with the ground (Slab) nor adjacent to ambient conditions above (Roof) is entered as a /HPXML/Building/BuildingDetails/Enclosure/Floors/Floor.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToSpace	idref		See [184]	See [185]		ID of attached space
ExteriorAdjacentTo	string		See [186]	Yes		Exterior adjacent space type
InteriorAdjacentTo	string		See [187]	Yes		Interior adjacent space type
FloorOrCeiling	string		See [188]	See [189]		Floor or ceiling from the perspective of the conditioned space
FloorType	element		See [190]	Yes		Floor type (for thermal mass)
Area	double	ft2	> 0	Yes		Gross area (including skylights for ceilings)
InteriorFinish/Type	string		See [191]	No	See [192]	Interior finish material
InteriorFinish/Thickness	double	in	>= 0	No	0.5	Interior finish thickness
RadiantBarrier	boolean			No	false	Presence of radiant barrier [193]
RadiantBarrierGrade	integer		>= 1, <= 3	No	1	Radiant barrier installation grade
Insulation/SystemIdentifier	id			Yes		Unique identifier
Insulation/AssemblyEffectiveRValue	double	F-ft2-hr/Btu	> 0	Yes		Assembly R-value [194]

[184]

If AttachedToSpace provided, it must reference a Space (within a conditioned Zone).

[185]

AttachedToSpace only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces) and the surface is adjacent to conditioned space (and not adiabatic).

[186]

ExteriorAdjacentTo choices are “outside”, “attic - vented”, “attic - unvented”, “basement - conditioned”, “basement - unconditioned”, “crawlspace - vented”, “crawlspace - unvented”, “crawlspace - conditioned”, “garage”, “other housing unit”, “other heated space”, “other multifamily buffer space”, “other non-freezing space”, or “manufactured home underbelly”. See HPXML Locations for descriptions.

[187]

InteriorAdjacentTo choices are “conditioned space”, “attic - vented”, “attic - unvented”, “basement - conditioned”, “basement - unconditioned”, “crawlspace - vented”, “crawlspace - unvented”, “crawlspace - conditioned”, or “garage”. See HPXML Locations for descriptions.

[188]

FloorOrCeiling choices are “floor” or “ceiling”.

[189]

FloorOrCeiling only required for floors adjacent to “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”.

[190]

FloorType child element choices are WoodFrame, StructuralInsulatedPanel, SteelFrame, or SolidConcrete.

[191]

InteriorFinish/Type choices are “gypsum board”, “gypsum composite board”, “plaster”, “wood”, “other”, or “none”.

[192]

InteriorFinish/Type defaults to “gypsum board” if InteriorAdjacentTo is conditioned space and the surface is a ceiling, otherwise “none”.

[193]

RadiantBarrier intended for attic floors. Model assumes an emittance of 0.5 (reduced effectiveness due to accumulation of dust) per an ORNL article on radiant barriers.

[194]

AssemblyEffectiveRValue includes all material layers and interior/exterior air films. It should also include the effects of insulation gaps (installation grading), compressed insulation in cavities, and/or reduced attic floor insulation thickness at the eaves per ANSI/RESNET/ICC 301-2022. For a manufactured home belly where the area of the belly wrap is different and usually greater than the floor area, the AssemblyEffectiveRValue should be adjusted to account for the surface area of the belly wrap and insulation.

HPXML Slabs

Each space type that borders the ground (i.e., basement, crawlspace, garage, and slab-on-grade foundation) should have a slab entered as an /HPXML/Building/BuildingDetails/Enclosure/Slabs/Slab.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToSpace	idref		See [195]	See [196]		ID of attached space
InteriorAdjacentTo	string		See [197]	Yes		Interior adjacent space type
Area	double	ft2	> 0	Yes		Gross area
Thickness	double	in	>= 0	No	See [198]	Thickness [199]
ExposedPerimeter	double	ft	>= 0	Yes		Perimeter exposed to ambient conditions [200]
DepthBelowGrade	double	ft	>= 0	No	See [201]	Depth from the top of the slab surface to grade
PerimeterInsulation/SystemIdentifier	id			Yes		Unique identifier
PerimeterInsulation/Layer/NominalRValue	double	F-ft2-hr/Btu	>= 0	Yes		R-value of vertical insulation (see figure below)
PerimeterInsulation/Layer/InsulationDepth	double	ft	>= 0	Yes		Depth from top of slab to bottom of vertical insulation
ExteriorHorizontalInsulation/SystemIdentifier	id			See [202]		Unique identifier
ExteriorHorizontalInsulation/Layer/NominalRValue	double	F-ft2-hr/Btu	>= 0	No	0	R-value of exterior horizontal insulation (see figure below) [203]
ExteriorHorizontalInsulation/Layer/InsulationWidth	double	ft	>= 0	No	0	Width of exterior horizontal insulation from slab edge outward
ExteriorHorizontalInsulation/Layer/InsulationDepthBelowGrade	double	ft	>= 0	No	0	Depth from grade to the top of exterior horizontal insulation
UnderSlabInsulation/SystemIdentifier	id			Yes		Unique identifier
UnderSlabInsulation/Layer/NominalRValue	double	F-ft2-hr/Btu	>= 0	Yes		R-value of horizontal insulation (see figure below)
UnderSlabInsulation/Layer/InsulationWidth	double	ft	>= 0	See [204]		Width from slab edge inward of horizontal insulation
UnderSlabInsulation/Layer/InsulationSpansEntireSlab	boolean			See [205]		Whether horizontal insulation spans entire slab
extension/GapInsulationRValue	double	F-ft2-hr/Btu	>= 0	No	See [206]	R-value of gap insulation (see figure below)
extension/CarpetFraction	double	frac	>= 0, <= 1	No	See [207]	Fraction of slab covered by carpet
extension/CarpetRValue	double	F-ft2-hr/Btu	>= 0	No	See [208]	Carpet R-value

[195]

If AttachedToSpace provided, it must reference a Space (within a conditioned Zone).

[196]

AttachedToSpace only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces) and the surface is adjacent to conditioned space.

[197]

InteriorAdjacentTo choices are “conditioned space”, “basement - conditioned”, “basement - unconditioned”, “crawlspace - vented”, “crawlspace - unvented”, “crawlspace - conditioned”, or “garage”. See HPXML Locations for descriptions.

[198]

If Thickness not provided, defaults to 0 when adjacent to crawlspace and 4 inches for all other cases.

[199]

For a crawlspace with a dirt floor, enter a thickness of zero.

[200]

ExposedPerimeter includes any slab length that falls along the perimeter of the building’s footprint (i.e., is exposed to ground or outdoor air conditions). See the figure below for an example of calculating slab exposed perimeter.

[201]

If DepthBelowGrade not provided, defaults to zero for foundation types without walls. For foundation types with walls, DepthBelowGrade is ignored as the slab’s position relative to grade is determined by the FoundationWall/DepthBelowGrade value(s).

[202]

SystemIdentifier only required if ExteriorHorizontalInsulation is provided.

[203]

Exterior horizontal insulation (sometimes called wing or skirt insulation) is typically used in colder regions with frost-susceptible soils to prevent the slab from heaving.

[204]

InsulationWidth only required if InsulationSpansEntireSlab=true is not provided.

[205]

InsulationSpansEntireSlab=true only required if InsulationWidth is not provided.

[206]

If GapInsulationRValue not provided, defaults to 5.0 if there is under slab (horizontal) insulation, otherwise 0.0.

[207]

If CarpetFraction not provided, defaults to 0.8 when adjacent to conditioned space, otherwise 0.0.

[208]

If CarpetRValue not provided, defaults to 2.0 when adjacent to conditioned space, otherwise 0.0.

An example of calculating slab exposed perimeter is shown below:

As illustrated above, basement slab edge adjacent to a garage slab or crawlspace is not considered exposed perimeter. It is quite uncommon for a slab to have an exposed perimeter of zero. Heat transfer is only calculated for the length of exposed perimeter; the rest of the perimeter is assumed to have minimal heat transfer.

Slab insulation locations can be visualized in the figure below:

HPXML Windows

Each window or glass door area is entered as a /HPXML/Building/BuildingDetails/Enclosure/Windows/Window.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Area	double	ft2	> 0	Yes		Total area [209]
Azimuth or Orientation	integer or string	deg or direction	>= 0, <= 359 or See [210]	Yes		Direction (clockwise from North)
UFactor and/or GlassLayers	double or string	Btu/F-ft2-hr	> 0 or See [211]	Yes		Full-assembly NFRC U-factor or glass layers description [212]
SHGC and/or GlassLayers	double or string		> 0, < 1	Yes		Full-assembly NFRC solar heat gain coefficient or glass layers description
ExteriorShading	element			No	<none>	Presence of exterior shading [213]
InteriorShading	element			No	<present>	Presence of interior shading [214]
InsectScreen	element			No	<none>	Presence of insect screen [215]
StormWindow	element			No	<none>	Presence of storm window [216]
Overhangs	element			No	<none>	Presence of overhangs (including roof eaves) [217]
FractionOperable	double	frac	>= 0, <= 1	No	0.67	Operable fraction [218]
AttachedToWall	idref		See [219]	Yes		ID of attached wall

[209]

For bay or garden windows, this should represent the total area, not just the primary flat exposure. The ratio of total area to primary flat exposure is typically around 1.15 for bay windows and 2.0 for garden windows.

[210]

Orientation choices are “northeast”, “east”, “southeast”, “south”, “southwest”, “west”, “northwest”, or “north”.

[211]

GlassLayers choices are “single-pane”, “double-pane”, “triple-pane”, or “glass block”.

[212]

If GlassLayers is provided, additional inputs are described in UFactor/SHGC Lookup.

[213]

If ExteriorShading is provided, additional inputs are described in HPXML Exterior Shading.

[214]

If InteriorShading is provided, additional inputs are described in HPXML Interior Shading.

[215]

If InsectScreen is provided, additional inputs are described in HPXML Insect Screen.

[216]

If StormWindow is provided, additional inputs are described in HPXML Storm Window.

[217]

If Overhangs is provided, additional inputs are described in HPXML Overhangs.

[218]

FractionOperable reflects whether the windows are operable (can be opened), not how they are used by the occupants. If a Window represents a single window, the value should be 0 or 1. If a Window represents multiple windows, the value is calculated as the total window area for any operable windows divided by the total window area. The total open window area for natural ventilation is calculated using A) the operable fraction, B) the assumption that 50% of the area of operable windows can be open, and C) the assumption that 20% of that openable area is actually opened by occupants whenever outdoor conditions are favorable for cooling. See additional inputs in Natural Ventilation.

[219]

AttachedToWall must reference a Wall or FoundationWall.

UFactor/SHGC Lookup

If UFactor and SHGC are not provided and GlassLayers is not “glass block”, additional information is entered in Window.

Element	Type	Units	Constraints	Required	Default	Notes
FrameType	element		See [220]	Yes		Type of frame
FrameType/*/ThermalBreak	boolean		See [221]	No	false	Whether the Aluminum or Metal frame has a thermal break
GlassType	string		See [222]	No	clear	Type of glass
GasFill	string		See [223]	No	See [224]	Type of gas inside double/triple-pane windows

[220]

FrameType child element choices are Aluminum, Fiberglass, Metal, Vinyl, or Wood.

[221]

ThermalBreak is only valid if FrameType is Aluminum or Metal.

[222]

GlassType choices are “clear”, “low-e”, “low-e, high-solar-gain”, “low-e, low-solar-gain”, “tinted”, “tinted/reflective”, or “reflective”.

[223]

GasFill choices are “air”, “argon”, “krypton”, “xenon”, “nitrogen”, or “other”.

[224]

If GasFill not provided, defaults to “air” for double-pane, non-low-e windows and “argon” for double-pane, low-e or triple-pane windows.

If UFactor and SHGC are not provided, they are defaulted as follows:

GlassLayers	FrameType	ThermalBreak	GlassType	GasFill	UFactor	SHGC
single-pane	Aluminum, Metal	false	“clear”, “reflective”	–	1.27	0.75
single-pane	Fiberglass, Vinyl, Wood	–	“clear”, “reflective”	–	0.89	0.64
single-pane	Aluminum, Metal	false	“tinted”, “tinted/reflective”	–	1.27	0.64
single-pane	Fiberglass, Vinyl, Wood	–	“tinted”, “tinted/reflective”	–	0.89	0.54
double-pane	Aluminum, Metal	false	“clear”, “reflective”	air	0.81	0.67
double-pane	Aluminum, Metal	true	“clear”, “reflective”	air	0.60	0.67
double-pane	Fiberglass, Vinyl, Wood	–	“clear”, “reflective”	air	0.51	0.56
double-pane	Aluminum, Metal	false	“tinted”, “tinted/reflective”	air	0.81	0.55
double-pane	Aluminum, Metal	true	“tinted”, “tinted/reflective”	air	0.60	0.55
double-pane	Fiberglass, Vinyl, Wood	–	“tinted”, “tinted/reflective”	air	0.51	0.46
double-pane	Fiberglass, Vinyl, Wood	–	“low-e”, “low-e, high-solar-gain”	air	0.42	0.52
double-pane	Aluminum, Metal	true	“low-e”, “low-e, high-solar-gain”	<any but air>	0.47	0.62
double-pane	Fiberglass, Vinyl, Wood	–	“low-e”, “low-e, high-solar-gain”	<any but air>	0.39	0.52
double-pane	Aluminum, Metal	false	“low-e, low-solar-gain”	air	0.67	0.37
double-pane	Aluminum, Metal	true	“low-e, low-solar-gain”	air	0.47	0.37
double-pane	Fiberglass, Vinyl, Wood	–	“low-e, low-solar-gain”	air	0.39	0.31
double-pane	Fiberglass, Vinyl, Wood	–	“low-e, low-solar-gain”	<any but air>	0.36	0.31
triple-pane	Fiberglass, Vinyl, Wood	–	“low-e”, “low-e, high-solar-gain”	<any but air>	0.27	0.31
glass block	–	–	–	–	0.60	0.60

Warning

OpenStudio-HPXML will return an error if the combination of window properties is not in the above table.

HPXML Exterior Shading

If exterior shading is specified, additional information is entered in ExteriorShading. Either winter/summer shading coefficients can be directly provided, or they can be defaulted from the other inputs.

Element	Type	Units	Constraints	Required	Default	Notes
Type	string		See [225]	No	See [226]	Shading type
SummerFractionCovered	double	frac	>= 0, <= 1	No	See [227]	Fraction of window area covered by shading in summer
WinterFractionCovered	double	frac	>= 0, <= 1	No	See [228]	Fraction of window area covered by shading in winter
SummerShadingCoefficient	double	frac	>= 0, <= 1	No	See [229]	Total summer shading coefficient for modeling (1=transparent, 0=opaque)
WinterShadingCoefficient	double	frac	>= 0, <= 1	No	See [230]	Total winter shading coefficient for modeling (1=transparent, 0=opaque)

[225]

Type choices are “external overhangs”, “awnings”, “solar screens”, “solar film”, “deciduous tree”, “evergreen tree”, “building”, “other”, or “none”.

[226]

If Type not provided, and either SummerShadingCoefficient or WinterShadingCoefficient not provided, defaults to “none”.

[227]

If SummerFractionCovered not provided, defaults to 1.0 for solar screens/solar film/overhangs/awnings and 0.5 for trees/other/building.

[228]

If WinterFractionCovered not provided, defaults to 1.0 for solar screens/solar film/overhangs/awnings, 0.5 for evergreen tree/other/building, and 0.25 for deciduous tree.

[229]

If SummerShadingCoefficient not provided, defaults to 1.0 if Type=”none”, otherwise calculated as follows:

SummerShadingCoefficient = SummerFractionCovered * C1 + (1 - SummerFractionCovered) * 1.0

- external overhangs or awnings: C1=0.0 (unless HPXML Overhangs are specified, in which case geometric shading is explicitly modeled)

- solar screens: C1=0.3 (Based on Table A.3.4 of MulTEA Engineering Manual Version 1)

- solar film: C1=0.7 (Based on Table A.3.4 of MulTEA Engineering Manual Version 1)

- deciduous tree or evergreen tree: C1=0.0

- building: C1=0.0 (unless HPXML Neighbor Buildings are specified, in which case geometric shading is explicitly modeled)

- other: C1=0.5

[230]

If WinterShadingCoefficient not provided, defaults to 1.0 if Type=”none”, otherwise calculated using same approach as SummerShadingCoefficient.

Note

OpenStudio-HPXML directly uses only the SummerShadingCoefficient and WinterShadingCoefficient values (user provided or defaulted) in the energy model. Summer vs winter shading seasons are determined per HPXML Shading Control.

HPXML Interior Shading

If interior shading is specified, additional information is entered in InteriorShading. Either winter/summer shading coefficients can be directly provided, or they can be defaulted from the other inputs.

Element	Type	Units	Constraints	Required	Default	Notes
Type	string		See [231]	No	See [232]	Shading type
BlindsSummerClosedOrOpen	string		See [233]	No	half open	Blinds position in summer (only used if shading type is blinds)
BlindsWinterClosedOrOpen	string		See [234]	No	half open	Blinds position in winter (only used if shading type is blinds)
SummerFractionCovered	double	frac	>= 0, <= 1	No	See [235]	Fraction of window area covered by shading in summer
WinterFractionCovered	double	frac	>= 0, <= 1	No	See [236]	Fraction of window area covered by shading in winter
SummerShadingCoefficient	double	frac	>= 0, <= 1	No	See [237]	Total summer shading coefficient for modeling (1=transparent, 0=opaque)
WinterShadingCoefficient	double	frac	>= 0, <= 1	No	See [238]	Total winter shading coefficient for modeling (1=transparent, 0=opaque)

[231]

Type choices are “light blinds”, “medium blinds”, “dark blinds”, “light shades”, “medium shades”, “dark shades”, “light curtains”, “medium curtains”, “dark curtains”, “other”, or “none”.

[232]

If Type not provided, and either SummerShadingCoefficient or WinterShadingCoefficient not provided, defaults to “light curtains” if not glass block windows and “none” for glass block windows.

[233]

BlindsSummerClosedOrOpen choices are “closed”, “open”, or “half open”.

[234]

BlindsWinterClosedOrOpen choices are “closed”, “open”, or “half open”.

[235]

If SummerFractionCovered not provided, defaults to 1.0 for blinds and 0.5 for shades/curtains/other.

[236]

If WinterFractionCovered not provided, defaults to 1.0 for blinds and 0.5 for shades/curtains/other.

[237]

If SummerShadingCoefficient not provided, defaults to 1.0 if Type=”none”, otherwise calculated based on Chapter 15 Table 14 of ASHRAE 2021 Handbook of Fundamentals:

SummerShadingCoefficient = SummerFractionCovered * (C1 - (C2 * WindowSHGC)) + (1 - SummerFractionCovered) * 1.0

where:

- dark curtains: C1=0.98, C2=0.25

- medium curtains: C1=0.94, C2=0.37

- light curtains: C1=0.84, C2=0.42

- dark shades: C1=0.98, C2=0.33

- medium shades: C1=0.9, C2=0.38

- light shades: C1=0.82, C2=0.42

- dark blinds, closed: C1=0.98, C2=0.25

- medium blinds, closed: C1=0.90, C2=0.41

- light blinds, closed: C1=0.78, C2=0.47

- dark blinds, half open: C1=1.0, C2=0.19

- medium blinds, half open: C1=0.95, C2=0.26

- light blinds, half open: C1=0.93, C2=0.38

- dark blinds, open: C1=0.99, C2=0.0

- medium blinds, open: C1=0.98, C2=0.0

- light blinds, open: C1=0.98, C2=0.0

- other: C1=0.5, C2=0.0

[238]

If WinterShadingCoefficient not provided, defaults to 1.0 if Type=”none”, otherwise calculated using same approach as SummerShadingCoefficient.

Note

OpenStudio-HPXML directly uses only the SummerShadingCoefficient and WinterShadingCoefficient values (user provided or defaulted) in the energy model. Summer vs winter shading seasons are determined per HPXML Shading Control.

HPXML Insect Screen

If an insect screen is specified, additional information is entered in InsectScreen. Either winter/summer shading coefficients can be directly provided, or they can be defaulted from the other inputs.

Element	Type	Units	Constraints	Required	Default	Notes
Location	string		See [239]	No	exterior	Whether the screen is on the interior or exterior of the glass
SummerFractionCovered	double	frac	>= 0, <= 1	No	See [240]	Fraction of window area covered in the summer
WinterFractionCovered	double	frac	>= 0, <= 1	No	See [241]	Fraction of window area covered in the winter
SummerShadingCoefficient	double	frac	>= 0, <= 1	No	See [242]	Interior summer shading coefficient for modeling (1=transparent, 0=opaque)
WinterShadingCoefficient	double	frac	>= 0, <= 1	No	See [243]	Interior winter shading coefficient for modeling (1=transparent, 0=opaque)

[239]

Location choices are “interior” or “exterior”.

[240]

If SummerFractionCovered not provided, defaults to the same value as FractionOperable.

[241]

If WinterFractionCovered not provided, defaults to the same value as FractionOperable.

[242]

If SummerShadingCoefficient not provided, calculated based on Chapter 15 Table 14 of ASHRAE 2021 Handbook of Fundamentals:

SummerShadingCoefficient = SummerFractionCovered * (C1 - (C2 * WindowSHGC)) + (1 - SummerFractionCovered) * 1.0

where:

- exterior: C1=0.64, C2=0.0

- interior: C1=0.99, C2=0.1

[243]

If WinterShadingCoefficient not provided, calculated using same approach as SummerShadingCoefficient.

Note

OpenStudio-HPXML directly uses only the SummerShadingCoefficient and WinterShadingCoefficient values (user provided or defaulted) in the energy model. Summer vs winter shading seasons are determined per HPXML Shading Control.

HPXML Storm Window

If a storm window is specified, additional information is entered in StormWindow.

Element	Type	Units	Constraints	Required	Default	Notes
GlassType	string		See [244]	No	<none>	Type of storm window glass

[244]

GlassType choices are “clear” or “low-e”. The UFactor and SHGC of the window will be adjusted depending on the GlassType, based on correlations derived using data reported by PNNL.

- clear storm windows: U-factor = U-factor of base window - (0.6435 * U-factor of base window - 0.1533); SHGC = 0.9 * SHGC of base window

- low-e storm windows: U-factor = U-factor of base window - (0.766 * U-factor of base window - 0.1532); SHGC = 0.8 * SHGC of base window

Note that a storm window is not allowed for a window with U-factor lower than 0.45.

HPXML Overhangs

If overhangs are specified, additional information is entered in Overhangs.

Element	Type	Units	Constraints	Required	Default	Notes
Depth	double	ft	>= 0	Yes		Depth of overhang
DistanceToTopOfWindow	double	ft	>= 0	Yes		Vertical distance from overhang to top of window
DistanceToBottomOfWindow	double	ft	See [245]	Yes		Vertical distance from overhang to bottom of window [246]

[245]

The difference between DistanceToBottomOfWindow and DistanceToTopOfWindow defines the height of the window.

[246]

When Depth is non-zero, DistanceToBottomOfWindow must be greater than DistanceToTopOfWindow.

Natural Ventilation

If operable windows are defined, the availability of natural ventilation is entered in /HPXML/Building/BuildingDetails/BuildingSummary/extension.

Element	Type	Units	Constraints	Required	Default	Notes
NaturalVentilationAvailabilityDaysperWeek	integer	days/week	>= 0, <= 7	No	3 [247]	How often windows can be opened by occupants for natural ventilation

[247]

Default of 3 days per week (Monday/Wednesday/Friday) is based on 2010 BAHSP.

HPXML Skylights

Each skylight is entered as a /HPXML/Building/BuildingDetails/Enclosure/Skylights/Skylight.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Area	double	ft2	> 0	Yes		Total area [248]
Azimuth or Orientation	integer or string	deg or direction	>= 0, <= 359 or See [249]	Yes		Direction (clockwise from North)
UFactor and/or GlassLayers	double or string	Btu/F-ft2-hr	> 0 or See [250]	Yes		Full-assembly NFRC U-factor or glass layers description [251]
SHGC and/or GlassLayers	double or string		> 0, < 1	Yes		Full-assembly NFRC solar heat gain coefficient or glass layers description
ExteriorShading	element			No	<none>	Presence of exterior shading [252]
InteriorShading	element			No	<none>	Presence of interior shading [253]
StormWindow	element			No	<none>	Presence of storm window [254]
AttachedToRoof	idref		See [255]	Yes		ID of attached roof
AttachedToFloor	idref		See [256]	See [257]		ID of attached attic floor
extension/Curb	element			No	<none>	Presence of curb (skylight wall above the roof deck) [258]
extension/Shaft	element			No	<none>	Presence of shaft (skylight wall below the roof deck) [259]

[248]

For dome skylights, this should represent the total area, not just the primary flat exposure. The ratio of total area to primary flat exposure is typically around 1.25 for dome skylights.

[249]

Orientation choices are “northeast”, “east”, “southeast”, “south”, “southwest”, “west”, “northwest”, or “north”

[250]

GlassLayers choices are “single-pane”, “double-pane”, or “triple-pane”.

[251]

If GlassLayers is provided, additional inputs are described in UFactor/SHGC Lookup.

[252]

If ExteriorShading is provided, additional inputs are described in HPXML Exterior Shading.

[253]

If InteriorShading is provided, additional inputs are described in HPXML Interior Shading.

[254]

If StormWindow is provided, additional inputs are described in HPXML Storm Window.

[255]

AttachedToRoof must reference a Roof.

[256]

AttachedToFloor must reference a Floor.

[257]

AttachedToFloor required if the attached roof is not adjacent to conditioned space (i.e., there is a skylight shaft).

[258]

If extension/Curb is provided, additional inputs are described in Skylight Curb.

[259]

If extension/Shaft is provided, additional inputs are described in Skylight Shaft. The skylight shaft will be modeled similar to an attic knee wall.

UFactor/SHGC Lookup

If UFactor and SHGC are not provided and GlassLayers is not “glass block”, additional information is entered in Skylight.

Element	Type	Units	Constraints	Required	Default	Notes
FrameType	element		See [260]	Yes		Type of frame
FrameType/*/ThermalBreak	boolean		See [261]	No	false	Whether the Aluminum or Metal frame has a thermal break
GlassType	string		See [262]	No	<none>	Type of glass
GasFill	string		See [263]	No	See [264]	Type of gas inside double/triple-pane skylights

[260]

FrameType child element choices are Aluminum, Fiberglass, Metal, Vinyl, or Wood.

[261]

ThermalBreak is only valid if FrameType is Aluminum or Metal.

[262]

GlassType choices are “clear”, “low-e”, “low-e, high-solar-gain”, “low-e, low-solar-gain”, “tinted”, “tinted/reflective”, or “reflective”.

[263]

GasFill choices are “air”, “argon”, “krypton”, “xenon”, “nitrogen”, or “other”.

[264]

If GasFill not provided, defaults to “air” for double-pane, non-low-e skylights and “argon” for double-pane, low-e or triple-pane skylights.

If UFactor and SHGC are not provided, they are defaulted as follows:

GlassLayers	FrameType	ThermalBreak	GlassType	GasFill	UFactor	SHGC
single-pane	Aluminum, Metal	false	“clear”, “reflective”	–	1.98	0.75
single-pane	Fiberglass, Vinyl, Wood	–	“clear”, “reflective”	–	1.47	0.64
single-pane	Aluminum, Metal	false	“tinted”, “tinted/reflective”	–	1.98	0.64
single-pane	Fiberglass, Vinyl, Wood	–	“tinted”, “tinted/reflective”	–	1.47	0.54
double-pane	Aluminum, Metal	false	“clear”, “reflective”	air	1.30	0.67
double-pane	Aluminum, Metal	true	“clear”, “reflective”	air	1.10	0.67
double-pane	Fiberglass, Vinyl, Wood	–	“clear”, “reflective”	air	0.84	0.56
double-pane	Aluminum, Metal	false	“tinted”, “tinted/reflective”	air	1.30	0.55
double-pane	Aluminum, Metal	true	“tinted”, “tinted/reflective”	air	1.10	0.55
double-pane	Fiberglass, Vinyl, Wood	–	“tinted”, “tinted/reflective”	air	0.84	0.46
double-pane	Fiberglass, Vinyl, Wood	–	“low-e”, “low-e, high-solar-gain”	air	0.74	0.52
double-pane	Aluminum, Metal	true	“low-e”, “low-e, high-solar-gain”	<any but air>	0.95	0.62
double-pane	Fiberglass, Vinyl, Wood	–	“low-e”, “low-e, high-solar-gain”	<any but air>	0.68	0.52
double-pane	Aluminum, Metal	false	“low-e, low-solar-gain”	air	1.17	0.37
double-pane	Aluminum, Metal	true	“low-e, low-solar-gain”	air	0.98	0.37
double-pane	Fiberglass, Vinyl, Wood	–	“low-e, low-solar-gain”	air	0.71	0.31
double-pane	Fiberglass, Vinyl, Wood	–	“low-e, low-solar-gain”	<any but air>	0.65	0.31
triple-pane	Fiberglass, Vinyl, Wood	–	“low-e”, “low-e, high-solar-gain”	<any but air>	0.47	0.31
glass block	–	–	–	–	0.60	0.60

Warning

OpenStudio-HPXML will return an error if the combination of skylight properties is not in the above table.

HPXML Exterior Shading

If exterior shading is present, additional information is entered in ExteriorShading.

Element	Type	Units	Constraints	Required	Default	Notes
SummerShadingCoefficient	double	frac	>= 0, <= 1	No	1.0	Exterior summer shading coefficient (1=transparent, 0=opaque)
WinterShadingCoefficient	double	frac	>= 0, <= 1	No	1.0	Exterior winter shading coefficient (1=transparent, 0=opaque)

Note

Summer vs winter shading seasons are determined per HPXML Shading Control.

HPXML Interior Shading

If interior shading is present, additional information is entered in InteriorShading.

Element	Type	Units	Constraints	Required	Default	Notes
SummerShadingCoefficient	double	frac	>= 0, <= 1	No	1.0	Interior summer shading coefficient (1=transparent, 0=opaque)
WinterShadingCoefficient	double	frac	>= 0, <= 1	No	1.0	Interior winter shading coefficient (1=transparent, 0=opaque)

Note

Summer vs winter shading seasons are determined per HPXML Shading Control.

HPXML Storm Window

If a storm window is specified, additional information is entered in StormWindow.

Element	Type	Units	Constraints	Required	Default	Notes
GlassType	string		See [265]	No	<none>	Type of storm window glass

[265]

GlassType choices are “clear” or “low-e”. The UFactor and SHGC of the skylight will be adjusted depending on the GlassType, based on correlations derived using data reported by PNNL.

- clear storm windows: U-factor = U-factor of base window - (0.6435 * U-factor of base window - 0.1533); SHGC = 0.9 * SHGC of base window

- low-e storm windows: U-factor = U-factor of base window - (0.766 * U-factor of base window - 0.1532); SHGC = 0.8 * SHGC of base window

Note that a storm window is not allowed for a skylight with U-factor lower than 0.45.

Skylight Curb

If the skylight has a curb, additional information is entered in Skylight.

Element	Type	Units	Constraints	Required	Default	Notes
extension/Curb/Area	double	ft2	> 0	Yes		Total area including all sides
extension/Curb/AssemblyEffectiveRValue	double	F-ft2-hr/Btu	> 0	Yes		Assembly R-value [266]

[266]

AssemblyEffectiveRValue includes all material layers and interior/exterior air films.

Skylight Shaft

If the skylight has a shaft, additional information is entered in Skylight.

Element	Type	Units	Constraints	Required	Default	Notes
extension/Shaft/Area	double	ft2	> 0	Yes		Total area including all sides
extension/Shaft/AssemblyEffectiveRValue	double	F-ft2-hr/Btu	> 0	Yes		Assembly R-value [267]

[267]

AssemblyEffectiveRValue includes all material layers and interior/exterior air films.

HPXML Doors

Each door with opaque area is entered as a /HPXML/Building/BuildingDetails/Enclosure/Doors/Door.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToWall	idref		See [268]	Yes		ID of attached wall
Area	double	ft2	> 0	Yes		Total opaque area [269]
Azimuth or Orientation	integer or string	deg	>= 0, <= 359 or See [270]	No	See [271]	Direction (clockwise from North)
RValue	double	F-ft2-hr/Btu	> 0	Yes		R-value [272]

[268]

AttachedToWall must reference a Wall or FoundationWall.

[269]

Any glass area in the door should be modeled using HPXML Windows. For example, if a 30 ft2 door has 10 ft2 of glass, the door area should be entered as 20 ft2 (with a separate Window for the remaining 10 ft2).

[270]

Orientation choices are “northeast”, “east”, “southeast”, “south”, “southwest”, “west”, “northwest”, or “north”

[271]

If neither Azimuth nor Orientation nor AttachedToWall azimuth provided, defaults to the azimuth with the largest surface area defined in the HPXML file.

[272]

RValue includes interior/exterior air films and presence of any storm door.

HPXML Partition Wall Mass

Partition wall mass in the conditioned space is entered as /HPXML/Building/BuildingDetails/Enclosure/extension/PartitionWallMass.

Element	Type	Units	Constraints	Required	Default	Notes
AreaFraction	double	frac	>= 0	No	1.0	Fraction of both sides of wall area to conditioned floor area
InteriorFinish/Type	string		See [273]	No	gypsum board	Interior finish material
InteriorFinish/Thickness	double	in	>= 0	No	0.5	Interior finish thickness

[273]

InteriorFinish/Type choices are “gypsum board”, “gypsum composite board”, “plaster”, “wood”, “other”, or “none”.

HPXML Furniture Mass

Furniture mass in the conditioned space is entered as /HPXML/Building/BuildingDetails/Enclosure/extension/FurnitureMass.

Element	Type	Units	Constraints	Required	Default	Notes
AreaFraction	double	frac	>= 0	No	0.4	Fraction of conditioned floor area covered by furniture
Type	string		See [274]	No	light-weight	Type of furniture

[274]

Type choices are “light-weight” and “heavy-weight”.

Note

Light-weight furniture is modeled with a weight of 8 lb/ft2 of floor area and a density of 40 lb/ft3 while heavy-weight furniture is modeled with a weight of 16 lb/ft2 of floor area and a density of 80 lb/ft3.

HPXML Systems

The dwelling unit’s systems are entered in /HPXML/Building/BuildingDetails/Systems.

HPXML Heating Systems

The following heating system types can be modeled:

• Electric Resistance

• Furnace

• Wall Furnace

• Floor Furnace

• Boiler (In-Unit)

• Boiler (Shared)

• Stove

• Space Heater

• Fireplace

Electric Resistance

Each electric resistance heating system is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [275]	See [276]		ID of attached zone
HeatingSystemType/ElectricResistance	element			Yes		Type of heating system
HeatingSystemType/ElectricResistance/ElectricDistribution	string		See [277]	No	baseboard	Type of electric resistance distribution
HeatingSystemFuel	string		electricity	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [278]	Heating output capacity
AnnualHeatingEfficiency[Units="Percent"]/Value	double	frac	> 0, <= 1	Yes		Heating efficiency
FractionHeatLoadServed	double	frac	>= 0, <= 1 [279]	See [280]		Fraction of heating load served
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[275]

If AttachedToZone provided, it must reference a conditioned Zone.

[276]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[277]

ElectricDistribution choices are “baseboard”, “radiant floor”, or “radiant ceiling”.

[278]

Heating capacity autosized per ACCA Manual J/S based on heating design load.

[279]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[280]

FractionHeatLoadServed is required unless the heating system is a heat pump backup system (i.e., referenced by a HeatPump[BackupType="separate"]/BackupSystem; see HPXML Heat Pumps), in which case FractionHeatLoadServed is not allowed. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature.

Furnace

Each central furnace is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [281]	See [282]		ID of attached zone
UnitLocation	string		See [283]	No	See [284]	Location of air handler
DistributionSystem	idref		See [285]	Yes		ID of attached distribution system
HeatingSystemType/Furnace	element			Yes		Type of heating system
HeatingSystemType/Furnace/PilotLight	boolean			No	false	Presence of standing pilot light (older systems)
HeatingSystemType/Furnace/extension/PilotLightBtuh	double	Btu/hr	>= 0	No	500	Pilot light burn rate
HeatingSystemFuel	string		See [286]	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [287]	Heating output capacity
AnnualHeatingEfficiency[Units="AFUE"]/Value	double	frac	> 0, <= 1	Yes		Rated heating efficiency
FractionHeatLoadServed	double	frac	>= 0, <= 1 [288]	See [289]		Fraction of heating load served
extension/FanMotorType	string		See [290]	No	See [291]	Blower fan model type
extension/FanPowerWattsPerCFM	double	W/cfm	>= 0 [292]	No	See [293]	Blower fan efficiency at maximum fan speed
extension/HeatingDesignAirflowCFM	double	cfm	>= 0	No	240 cfm/ton	Blower fan heating design airflow rate
extension/AirflowDefectRatio	double	frac	>= -0.9, <= 9	No	0.0	Deviation between design/installed airflow rates [294]
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[281]

If AttachedToZone provided, it must reference a conditioned Zone.

[282]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[283]

UnitLocation choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, “other non-freezing space”, “roof deck”, “manufactured home belly”, or “unconditioned space”.

[284]

If UnitLocation not provided, defaults based on the distribution system:

- Air: supply duct location with the largest area, otherwise “conditioned space”

- DSE: “conditioned space” if FractionHeatLoadServed is 1, otherwise “unconditioned space”

[285]

HVACDistribution type must be Air Distribution (type: “regular velocity” or “gravity”) or Distribution System Efficiency (DSE).

[286]

HeatingSystemFuel choices are “electricity”, “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “wood”, or “wood pellets”.

[287]

Heating capacity autosized per ACCA Manual J/S based on heating design load.

[288]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[289]

FractionHeatLoadServed is required unless the heating system is a heat pump backup system (i.e., referenced by a HeatPump[BackupType="separate"]/BackupSystem; see HPXML Heat Pumps), in which case FractionHeatLoadServed is not allowed. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature.

[290]

FanMotorType choices are “PSC” (Permanent Split Capacitor) and “BPM” (Brushless Permanent Magnet). If there is a cooling system attached to the DistributionSystem, the heating and cooling systems cannot have different values for FanMotorType.

[291]

If FanMotorType is not provided and if there is a cooling system attached to the DistributionSystem, defaults to “PSC” if the attached cooling system CompressorType is “single stage”, else “BPM”; If there’s no cooling system attached, defaults to “PSC” if AFUE <= 0.9, else “BPM”.

[292]

If there is a cooling system attached to the DistributionSystem, the heating and cooling systems cannot have different values for FanPowerWattsPerCFM.

[293]

If FanPowerWattsPerCFM not provided, defaults to using attached central air conditioner W/cfm if available, else 0 W/cfm if gravity distribution system, else 0.5 W/cfm if FanMotorType is “PSC”, else 0.375 W/cfm if FanMotorType is “BPM”.

[294]

AirflowDefectRatio is defined as (InstalledAirflow - DesignAirflow) / DesignAirflow; a value of zero means no airflow defect. See ANSI/RESNET/ACCA 310-2020 for more information.

Wall Furnace

Each wall furnace is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [295]	See [296]		ID of attached zone
HeatingSystemType/WallFurnace	element			Yes		Type of heating system
HeatingSystemType/WallFurnace/PilotLight	boolean			No	false	Presence of standing pilot light (older systems)
HeatingSystemType/WallFurnace/extension/PilotLightBtuh	double	Btu/hr	>= 0	No	500	Pilot light burn rate
HeatingSystemFuel	string		See [297]	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [298]	Heating output capacity
AnnualHeatingEfficiency[Units="AFUE"]/Value	double	frac	> 0, <= 1	Yes		Rated heating efficiency
FractionHeatLoadServed	double	frac	>= 0, <= 1 [299]	See [300]		Fraction of heating load served
extension/FanPowerWatts	double	W	>= 0	No	0	Fan power
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[295]

If AttachedToZone provided, it must reference a conditioned Zone.

[296]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[297]

HeatingSystemFuel choices are “electricity”, “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “wood”, or “wood pellets”.

[298]

Heating capacity autosized per ACCA Manual J/S based on heating design load.

[299]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[300]

FractionHeatLoadServed is required unless the heating system is a heat pump backup system (i.e., referenced by a HeatPump[BackupType="separate"]/BackupSystem; see HPXML Heat Pumps), in which case FractionHeatLoadServed is not allowed. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature.

Floor Furnace

Each floor furnace is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [301]	See [302]		ID of attached zone
HeatingSystemType/FloorFurnace	element			Yes		Type of heating system
HeatingSystemType/FloorFurnace/PilotLight	boolean			No	false	Presence of standing pilot light (older systems)
HeatingSystemType/FloorFurnace/extension/PilotLightBtuh	double	Btu/hr	>= 0	No	500	Pilot light burn rate
HeatingSystemFuel	string		See [303]	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [304]	Heating output capacity
AnnualHeatingEfficiency[Units="AFUE"]/Value	double	frac	> 0, <= 1	Yes		Rated heating efficiency
FractionHeatLoadServed	double	frac	>= 0, <= 1 [305]	See [306]		Fraction of heating load served
extension/FanPowerWatts	double	W	>= 0	No	0	Fan power
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[301]

If AttachedToZone provided, it must reference a conditioned Zone.

[302]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[303]

HeatingSystemFuel choices are “electricity”, “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “wood”, or “wood pellets”.

[304]

Heating capacity autosized per ACCA Manual J/S based on heating design load.

[305]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[306]

FractionHeatLoadServed is required unless the heating system is a heat pump backup system (i.e., referenced by a HeatPump[BackupType="separate"]/BackupSystem; see HPXML Heat Pumps), in which case FractionHeatLoadServed is not allowed. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature.

Boiler (In-Unit)

Each in-unit boiler is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [307]	See [308]		ID of attached zone
UnitLocation	string		See [309]	No	See [310]	Location of boiler
DistributionSystem	idref		See [311]	Yes		ID of attached distribution system
HeatingSystemType/Boiler	element			Yes		Type of heating system
HeatingSystemType/Boiler/PilotLight	boolean			No	false	Presence of standing pilot light (older systems)
HeatingSystemType/Boiler/extension/PilotLightBtuh	double	Btu/hr	>= 0	No	500	Pilot light burn rate
HeatingSystemFuel	string		See [312]	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [313]	Heating output capacity
AnnualHeatingEfficiency[Units="AFUE"]/Value	double	frac	> 0, <= 1	Yes		Rated heating efficiency
FractionHeatLoadServed	double	frac	>= 0, <= 1 [314]	See [315]		Fraction of heating load served
ElectricAuxiliaryEnergy	double	kWh/yr	>= 0	No	See [316]	Electric auxiliary energy
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[307]

If AttachedToZone provided, it must reference a conditioned Zone.

[308]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[309]

UnitLocation choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, “other non-freezing space”, “roof deck”, “manufactured home belly”, or “unconditioned space”.

[310]

If UnitLocation not provided, defaults based on the distribution system:

- Hydronic: same default logic as HPXML Water Heating Systems

- DSE: “conditioned space” if FractionHeatLoadServed is 1, otherwise “unconditioned space”

[311]

HVACDistribution type must be Hydronic Distribution (type: “radiator”, “baseboard”, “radiant floor”, or “radiant ceiling”) or Distribution System Efficiency (DSE). Note: The choice of hydronic distribution type does not currently affect simulation results.

[312]

HeatingSystemFuel choices are “electricity”, “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “wood”, or “wood pellets”.

[313]

Heating capacity autosized per ACCA Manual J/S based on heating design load.

[314]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[315]

FractionHeatLoadServed is required unless the heating system is a heat pump backup system (i.e., referenced by a HeatPump[BackupType="separate"]/BackupSystem; see HPXML Heat Pumps), in which case FractionHeatLoadServed is not allowed. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature.

[316]

If ElectricAuxiliaryEnergy not provided, defaults as follows per ANSI/RESNET/ICC 301-2019:

- Oil boiler: 330 kWh/yr

- Gas boiler: 170 kWh/yr

Boiler (Shared)

Each shared boiler (serving multiple dwelling units) is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [317]	See [318]		ID of attached zone
UnitLocation	string		See [319]	No	other heated space	Location of boiler
DistributionSystem	idref		See [320]	Yes		ID of attached distribution system
IsSharedSystem	boolean		true	Yes		Whether it serves multiple dwelling units
NumberofUnitsServed	integer		> 1	Yes		Number of dwelling units served
HeatingSystemType/Boiler	element			Yes		Type of heating system
HeatingSystemType/Boiler/PilotLight	boolean			No	false	Presence of standing pilot light (older systems)
HeatingSystemType/Boiler/extension/PilotLightBtuh	double	Btu/hr	>= 0	No	500	Pilot light burn rate
HeatingSystemFuel	string		See [321]	Yes		Fuel type
AnnualHeatingEfficiency[Units="AFUE"]/Value	double	frac	> 0, <= 1	Yes		Rated heating efficiency
FractionHeatLoadServed	double	frac	>= 0, <= 1 [322]	See [323]		Fraction of heating load served
ElectricAuxiliaryEnergy or extension/SharedLoopWatts	double	kWh/yr or W	>= 0	No	See [324]	Electric auxiliary energy or shared loop power
ElectricAuxiliaryEnergy or extension/FanCoilWatts	double	kWh/yr or W	>= 0	No [325]		Electric auxiliary energy or fan coil power
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[317]

If AttachedToZone provided, it must reference a conditioned Zone.

[318]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[319]

UnitLocation choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, “other non-freezing space”, “roof deck”, “manufactured home belly”, or “unconditioned space”.

[320]

HVACDistribution type must be Hydronic Distribution (type: “radiator”, “baseboard”, “radiant floor”, “radiant ceiling”, or “water loop”) or Air Distribution (type: “fan coil”). If the shared boiler has “water loop” distribution, a Water-Loop-to-Air Heat Pump must also be specified. Note: The choice of hydronic distribution type does not currently affect simulation results; it is currently only used to know if there’s an attached water loop heat pump or not.

[321]

HeatingSystemFuel choices are “electricity”, “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “wood”, or “wood pellets”.

[322]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[323]

FractionHeatLoadServed is required unless the heating system is a heat pump backup system (i.e., referenced by a HeatPump[BackupType="separate"]/BackupSystem; see HPXML Heat Pumps), in which case FractionHeatLoadServed is not allowed. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature.

[324]

If ElectricAuxiliaryEnergy nor SharedLoopWatts provided, defaults as follows per ANSI/RESNET/ICC 301-2019:

- Shared boiler w/ baseboard: 220 kWh/yr

- Shared boiler w/ water loop heat pump: 265 kWh/yr

- Shared boiler w/ fan coil: 438 kWh/yr

[325]

FanCoilWatts only used if boiler connected to fan coil and SharedLoopWatts provided.

Stove

Each stove is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [326]	See [327]		ID of attached zone
HeatingSystemType/Stove	element			Yes		Type of heating system
HeatingSystemType/Stove/PilotLight	boolean			No	false	Presence of standing pilot light (older systems)
HeatingSystemType/Stove/extension/PilotLightBtuh	double	Btu/hr	>= 0	No	500	Pilot light burn rate
HeatingSystemFuel	string		See [328]	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [329]	Heating output capacity
AnnualHeatingEfficiency[Units="Percent"]/Value	double	frac	> 0, <= 1	Yes		Heating efficiency
FractionHeatLoadServed	double	frac	>= 0, <= 1 [330]	See [331]		Fraction of heating load served
extension/FanPowerWatts	double	W	>= 0	No	40	Fan power
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[326]

If AttachedToZone provided, it must reference a conditioned Zone.

[327]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[328]

HeatingSystemFuel choices are “electricity”, “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “wood”, or “wood pellets”.

[329]

Heating capacity autosized per ACCA Manual J/S based on heating design load.

[330]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[331]

FractionHeatLoadServed is required unless the heating system is a heat pump backup system (i.e., referenced by a HeatPump[BackupType="separate"]/BackupSystem; see HPXML Heat Pumps), in which case FractionHeatLoadServed is not allowed. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature.

Space Heater

Each space heater is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [332]	See [333]		ID of attached zone
HeatingSystemType/SpaceHeater	element			Yes		Type of heating system
HeatingSystemFuel	string		See [334]	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [335]	Heating output capacity
AnnualHeatingEfficiency[Units="Percent"]/Value	double	frac	> 0, <= 1	Yes		Heating efficiency
FractionHeatLoadServed	double	frac	>= 0, <= 1 [336]	See [337]		Fraction of heating load served
extension/FanPowerWatts	double	W	>= 0	No	0	Fan power
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[332]

If AttachedToZone provided, it must reference a conditioned Zone.

[333]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[334]

HeatingSystemFuel choices are “electricity”, “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “wood”, or “wood pellets”.

[335]

Heating capacity autosized per ACCA Manual J/S based on heating design load.

[336]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[337]

FractionHeatLoadServed is required unless the heating system is a heat pump backup system (i.e., referenced by a HeatPump[BackupType="separate"]/BackupSystem; see HPXML Heat Pumps), in which case FractionHeatLoadServed is not allowed. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature.

Fireplace

Each fireplace is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatingSystem. Instead of modeling fireplaces as serving a fraction of the heating load, fireplaces can be assigned a therm/year usage using HPXML Fuel Loads.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [338]	See [339]		ID of attached zone
HeatingSystemType/Fireplace	element			Yes		Type of heating system
HeatingSystemType/Fireplace/PilotLight	boolean			No	false	Presence of standing pilot light (older systems)
HeatingSystemType/Fireplace/extension/PilotLightBtuh	double	Btu/hr	>= 0	No	500	Pilot light burn rate
HeatingSystemFuel	string		See [340]	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [341]	Heating output capacity
AnnualHeatingEfficiency[Units="Percent"]/Value	double	frac	> 0, <= 1	Yes		Heating efficiency
FractionHeatLoadServed	double	frac	>= 0, <= 1 [342]	See [343]		Fraction of heating load served
extension/FanPowerWatts	double	W	>= 0	No	0	Fan power
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[338]

If AttachedToZone provided, it must reference a conditioned Zone.

[339]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[340]

HeatingSystemFuel choices are “electricity”, “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “wood”, or “wood pellets”.

[341]

Heating capacity autosized per ACCA Manual J/S based on heating design load.

[342]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[343]

FractionHeatLoadServed is required unless the heating system is a heat pump backup system (i.e., referenced by a HeatPump[BackupType="separate"]/BackupSystem; see HPXML Heat Pumps), in which case FractionHeatLoadServed is not allowed. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature.

HPXML Cooling Systems

The following cooling system types can be modeled:

• Central Air Conditioner

• Room Air Conditioner

• Packaged Terminal Air Conditioner

• Evaporative Cooler

• Mini-Split Air Conditioner

• Chiller (Shared)

• Cooling Tower (Shared)

Central Air Conditioner

Each central air conditioner is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/CoolingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [344]	See [345]		ID of attached zone
UnitLocation	string		See [346]	No	See [347]	Location of air handler
DistributionSystem	idref		See [348]	Yes		ID of attached distribution system
CoolingSystemType	string		central air conditioner	Yes		Type of cooling system
CoolingSystemFuel	string		electricity	Yes		Fuel type
CoolingCapacity	double	Btu/hr	>= 0	No	autosized [349]	Cooling output capacity
CompressorType	string		See [350]	Yes		Type of compressor
FractionCoolLoadServed	double	frac	>= 0, <= 1 [351]	Yes		Fraction of cooling load served
AnnualCoolingEfficiency[Units="SEER2" or Units="SEER"]/Value	double	Btu/Wh	> 0	Yes		Rated cooling efficiency [352]
AnnualCoolingEfficiency[Units="EER2" or Units="EER"]/Value	double	Btu/Wh	> 0 [353]	No	See [354]	Rated cooling efficiency [355]
CoolingDetailedPerformanceData	element			No	<none>	Cooling detailed performance data [356]
extension/FanMotorType	string		See [357]	No	See [358]	Blower fan model type
extension/FanPowerWattsPerCFM	double	W/cfm	>= 0 [359]	No	See [360]	Blower fan efficiency at maximum fan speed
extension/CoolingDesignAirflowCFM	double	cfm	>= 0	No	360 cfm/ton	Blower fan cooling design airflow rate
extension/AirflowDefectRatio	double	frac	>= -0.9, <= 9	No	0.0	Deviation between design/installed airflow rates [361]
extension/ChargeDefectRatio	double	frac	>= -0.9, <= 9	No	0.0	Deviation between design/installed refrigerant charges [362]
extension/CrankcaseHeaterPowerWatts	double	W	>= 0	No	See [363]	Crankcase heater power
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit
extension/EquipmentType	string		See [364]	No	split system	Equipment type only used for SEER/SEER2 and EER/EER2 conversions

[344]

If AttachedToZone provided, it must reference a conditioned Zone.

[345]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[346]

UnitLocation choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, “other non-freezing space”, “roof deck”, “manufactured home belly”, or “unconditioned space”.

[347]

If UnitLocation not provided, defaults based on the distribution system:

- Air: supply duct location with the largest area, otherwise “conditioned space”

- DSE: “conditioned space” if FractionCoolLoadServed is 1, otherwise “unconditioned space”

[348]

HVACDistribution type must be Air Distribution (type: “regular velocity”) or Distribution System Efficiency (DSE).

[349]

Cooling capacity autosized per ACCA Manual J/S based on cooling design load.

[350]

CompressorType choices are “single stage”, “two stage”, or “variable speed”.

[351]

The sum of all FractionCoolLoadServed (across all HVAC systems) must be less than or equal to 1.

[352]

If SEER provided, converted to SEER2 using ANSI/RESNET/ICC 301-2022 Addendum C. For example, SEER2 = SEER * 0.95 if EquipmentType is “split system”.

[353]

In addition, EER2 must be <= SEER2; EER must be < SEER.

[354]

If neither EER2 nor EER provided, EER2 defaults to (0.73 * SEER2 + 1.47) for single stage, (0.63 * SEER2 + 2.34) for two stage, and (0.31 * SEER2 + 6.45) for variable speed, based on a regression analysis of ENERGY STAR products.

[355]

If EER provided, converted to EER2 using ANSI/RESNET/ICC 301-2022 Addendum C. For example, EER2 = EER * 0.95 if EquipmentType is “split system”.

[356]

If CoolingDetailedPerformanceData is provided, see Detailed Cooling Performance Data.

[357]

FanMotorType choices are “PSC” (Permanent Split Capacitor) and “BPM” (Brushless Permanent Magnet). If there is a heating system attached to the DistributionSystem, the heating and cooling systems cannot have different values for FanMotorType.

[358]

If FanMotorType is not provided, defaults to using attached furnace FanMotorType if available, else “PSC” if CompressorType is “single stage”, else “BPM”.

[359]

If there is a heating system attached to the DistributionSystem, the heating and cooling systems cannot have different values for FanPowerWattsPerCFM.

[360]

If FanPowerWattsPerCFM not provided, defaults to using attached furnace W/cfm if available, else 0.5 W/cfm if FanMotorType is “PSC”, else 0.375 W/cfm if FanMotorType is “BPM”.

[361]

AirflowDefectRatio is defined as (InstalledAirflow - DesignAirflow) / DesignAirflow; a value of zero means no airflow defect. See ANSI/RESNET/ACCA 310-2020 for more information.

[362]

ChargeDefectRatio is defined as (InstalledCharge - DesignCharge) / DesignCharge; a value of zero means no refrigerant charge defect. A non-zero charge defect should typically only be applied for systems that are charged on site, not for systems that have pre-charged line sets. See ANSI/RESNET/ACCA 310-2020 for more information.

[363]

If CrankcaseHeaterPowerWatts not provided, defaults to 10 W per ton of rated cooling capacity per RESNET HERS Addendum 82.

[364]

EquipmentType choices are “split system”, “packaged system”, “small duct high velocity system”, or “space constrained system”.

Room Air Conditioner

Each room air conditioner is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/CoolingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [365]	See [366]		ID of attached zone
DistributionSystem	idref		See [367]	No		ID of attached distribution system
CoolingSystemType	string		room air conditioner	Yes		Type of cooling system
CoolingSystemFuel	string		electricity	Yes		Fuel type
CoolingCapacity	double	Btu/hr	>= 0	No	autosized [368]	Cooling output capacity
FractionCoolLoadServed	double	frac	>= 0, <= 1 [369]	Yes		Fraction of cooling load served
AnnualCoolingEfficiency[Units="CEER" or Units="EER"]/Value	double	Btu/Wh	> 0	Yes		Rated cooling efficiency
IntegratedHeatingSystemFuel	string		See [370]	No	<none>	Fuel type of integrated heater
extension/CrankcaseHeaterPowerWatts	double	W	>= 0	No	0.0	Crankcase heater power
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit

[365]

If AttachedToZone provided, it must reference a conditioned Zone.

[366]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[367]

DistributionSystem is only allowed to accommodate attaching a Central Fan Integrated Supply (CFIS) mechanical ventilation system to the ductless HVAC system. If DistributionSystem provided, HVACDistribution type must be Distribution System Efficiency (DSE) with a DSE of 1.

[368]

Cooling capacity autosized per ACCA Manual J/S based on cooling design load.

[369]

The sum of all FractionCoolLoadServed (across all HVAC systems) must be less than or equal to 1.

[370]

IntegratedHeatingSystemFuel choices are “electricity”, “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “wood”, or “wood pellets”.

If the room air conditioner has integrated heating, additional information is entered in CoolingSystem. Note that a room air conditioner with reverse cycle heating should be entered as a heat pump; see Room Air Conditioner w/ Reverse Cycle.

Element	Type	Units	Constraints	Required	Default	Notes
IntegratedHeatingSystemCapacity	double	Btu/hr	>= 0	No	autosized [371]	Heating output capacity of integrated heater
IntegratedHeatingSystemAnnualEfficiency[Units="Percent"]/Value	double	frac	> 0, <= 1	Yes		Efficiency of integrated heater
IntegratedHeatingSystemFractionHeatLoadServed	double	frac	>= 0, <= 1 [372]	Yes		Fraction of heating load served

[371]

Heating capacity autosized per ACCA Manual J/S based on heating design load.

[372]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

Packaged Terminal Air Conditioner

Each packaged terminal air conditioner (PTAC) is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/CoolingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [373]	See [374]		ID of attached zone
DistributionSystem	idref		See [375]	No		ID of attached distribution system
CoolingSystemType	string		packaged terminal air conditioner	Yes		Type of cooling system
CoolingSystemFuel	string		electricity	Yes		Fuel type
CoolingCapacity	double	Btu/hr	>= 0	No	autosized [376]	Cooling output capacity
FractionCoolLoadServed	double	frac	>= 0, <= 1 [377]	Yes		Fraction of cooling load served
AnnualCoolingEfficiency[Units="CEER" or Units="EER"]/Value	double	Btu/Wh	> 0	Yes		Rated cooling efficiency
IntegratedHeatingSystemFuel	string		See [378]	No	<none>	Fuel type of integrated heater
extension/CrankcaseHeaterPowerWatts	double	W	>= 0	No	0.0	Crankcase heater power
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit

[373]

If AttachedToZone provided, it must reference a conditioned Zone.

[374]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[375]

DistributionSystem is only allowed to accommodate attaching a Central Fan Integrated Supply (CFIS) mechanical ventilation system to the ductless HVAC system. If DistributionSystem provided, HVACDistribution type must be Distribution System Efficiency (DSE) with a DSE of 1.

[376]

Cooling capacity autosized per ACCA Manual J/S based on cooling design load.

[377]

The sum of all FractionCoolLoadServed (across all HVAC systems) must be less than or equal to 1.

[378]

IntegratedHeatingSystemFuel choices are “electricity”, “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “wood”, or “wood pellets”.

If the PTAC has integrated heating, additional information is entered in CoolingSystem. Note that a packaged terminal heat pump should be entered as a heat pump; see Packaged Terminal Heat Pump.

Element	Type	Units	Constraints	Required	Default	Notes
IntegratedHeatingSystemCapacity	double	Btu/hr	>= 0	No	autosized [379]	Heating output capacity of integrated heater
IntegratedHeatingSystemAnnualEfficiency[Units="Percent"]/Value	double	frac	> 0, <= 1	Yes		Efficiency of integrated heater
IntegratedHeatingSystemFractionHeatLoadServed	double	frac	>= 0, <= 1 [380]	Yes		Fraction of heating load served

[379]

Heating capacity autosized per ACCA Manual J/S based on heating design load.

[380]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

Evaporative Cooler

Each evaporative cooler is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/CoolingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [381]	See [382]		ID of attached zone
DistributionSystem	idref		See [383]	No		ID of attached distribution system
CoolingSystemType	string		evaporative cooler	Yes		Type of cooling system
CoolingSystemFuel	string		electricity	Yes		Fuel type
CoolingCapacity	double	Btu/hr	>= 0	No	autosized [384]	Cooling output capacity
FractionCoolLoadServed	double	frac	>= 0, <= 1 [385]	Yes		Fraction of cooling load served
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit

[381]

If AttachedToZone provided, it must reference a conditioned Zone.

[382]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[383]

If DistributionSystem provided, HVACDistribution type must be Air Distribution (type: “regular velocity”) or Distribution System Efficiency (DSE).

[384]

Cooling capacity autosized per ACCA Manual J/S based on cooling design load.

[385]

The sum of all FractionCoolLoadServed (across all HVAC systems) must be less than or equal to 1.

Mini-Split Air Conditioner

Each mini-split air conditioner is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/CoolingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [386]	See [387]		ID of attached zone
UnitLocation	string		See [388]	No	See [389]	Location of air handler
DistributionSystem	idref		See [390]	No		ID of attached distribution system
CoolingSystemType	string		mini-split	Yes		Type of cooling system
CoolingSystemFuel	string		electricity	Yes		Fuel type
CoolingCapacity	double	Btu/hr	>= 0	No	autosized [391]	Cooling output capacity
CompressorType	string		variable speed	Yes		Type of compressor
FractionCoolLoadServed	double	frac	>= 0, <= 1 [392]	Yes		Fraction of cooling load served
AnnualCoolingEfficiency[Units="SEER2" or Units="SEER"]/Value	double	Btu/Wh	> 0	Yes		Rated cooling efficiency [393]
AnnualCoolingEfficiency[Units="EER2" or Units="EER"]/Value	double	Btu/Wh	> 0 [394]	No	See [395]	Rated cooling efficiency [396]
CoolingDetailedPerformanceData	element			No	<none>	Cooling detailed performance data [397]
extension/FanMotorType	string		See [398]	No	BPM	Blower fan model type
extension/FanPowerWattsPerCFM	double	W/cfm	>= 0 [399]	No	See [400]	Blower fan efficiency at maximum fan speed
extension/CoolingDesignAirflowCFM	double	cfm	>= 0	No	360 cfm/ton	Blower fan cooling design airflow rate
extension/AirflowDefectRatio	double	frac	>= -0.9, <= 9	No	0.0	Deviation between design/installed airflow rates [401]
extension/ChargeDefectRatio	double	frac	>= -0.9, <= 9	No	0.0	Deviation between design/installed refrigerant charges [402]
extension/CrankcaseHeaterPowerWatts	double	W	>= 0	No	See [403]	Crankcase heater power
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit

[386]

If AttachedToZone provided, it must reference a conditioned Zone.

[387]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[388]

UnitLocation choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, “other non-freezing space”, “roof deck”, “manufactured home belly”, or “unconditioned space”.

[389]

If UnitLocation not provided, defaults based on the distribution system:

- Air: supply duct location with the largest area, otherwise “conditioned space”

- DSE: “conditioned space” if FractionCoolLoadServed is 1, otherwise “unconditioned space”

[390]

If DistributionSystem provided, HVACDistribution type must be Air Distribution (type: “regular velocity”) or Distribution System Efficiency (DSE).

[391]

Cooling capacity autosized per ACCA Manual J/S based on cooling design load.

[392]

The sum of all FractionCoolLoadServed (across all HVAC systems) must be less than or equal to 1.

[393]

If SEER provided, converted to SEER2 using ANSI/RESNET/ICC 301-2022 Addendum C, where SEER2 = SEER * 0.95 if ducted and SEER2 = SEER if ductless.

[394]

In addition, EER2 must be <= SEER2; EER must be < SEER.

[395]

If neither EER2 nor EER provided, EER2 defaults to (0.73 * SEER2 + 1.47) for single stage, (0.63 * SEER2 + 2.34) for two stage, and (0.31 * SEER2 + 6.45) for variable speed, based on a regression analysis of ENERGY STAR products.

[396]

If EER provided, converted to EER2 using ANSI/RESNET/ICC 301-2022 Addendum C, where EER2 = EER * 0.95 if ducted and EER2 = EER if ductless.

[397]

If CoolingDetailedPerformanceData is provided, see Detailed Cooling Performance Data.

[398]

FanMotorType choices are “PSC” (Permanent Split Capacitor) and “BPM” (Brushless Permanent Magnet). If there is a heating system attached to the DistributionSystem, the heating and cooling systems cannot have different values for FanMotorType.

[399]

If there is a heating system attached to the DistributionSystem, the heating and cooling systems cannot have different values for FanPowerWattsPerCFM.

[400]

FanPowerWattsPerCFM defaults to 0.07 W/cfm for ductless systems and 0.18 W/cfm for ducted systems.

[401]

AirflowDefectRatio is defined as (InstalledAirflow - DesignAirflow) / DesignAirflow; a value of zero means no airflow defect. A non-zero airflow defect can only be applied for systems attached to a distribution system. See ANSI/RESNET/ACCA 310-2020 for more information.

[402]

ChargeDefectRatio is defined as (InstalledCharge - DesignCharge) / DesignCharge; a value of zero means no refrigerant charge defect. A non-zero charge defect should typically only be applied for systems that are charged on site, not for systems that have pre-charged line sets. See ANSI/RESNET/ACCA 310-2020 for more information.

[403]

If CrankcaseHeaterPowerWatts not provided, defaults to 10 W per ton of rated cooling capacity per RESNET HERS Addendum 82.

Chiller (Shared)

Each shared chiller (serving multiple dwelling units) is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/CoolingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [404]	See [405]		ID of attached zone
DistributionSystem	idref		See [406]	Yes		ID of attached distribution system
IsSharedSystem	boolean		true	Yes		Whether it serves multiple dwelling units
NumberofUnitsServed	integer		> 1	Yes		Number of dwelling units served
CoolingSystemType	string		chiller	Yes		Type of cooling system
CoolingSystemFuel	string		electricity	Yes		Fuel type
CoolingCapacity	double	Btu/hr	>= 0	Yes		Total cooling output capacity
FractionCoolLoadServed	double	frac	>= 0, <= 1 [407]	Yes		Fraction of cooling load served
AnnualCoolingEfficiency[Units="kW/ton"]/Value	double	kW/ton	> 0	Yes		Rated cooling efficiency
extension/SharedLoopWatts	double	W	>= 0	Yes		Pumping and fan power serving the system
extension/FanCoilWatts	double	W	>= 0	See [408]		Fan coil power
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit

[404]

If AttachedToZone provided, it must reference a conditioned Zone.

[405]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[406]

HVACDistribution type must be Hydronic Distribution (type: “radiator”, “baseboard”, “radiant floor”, “radiant ceiling”, or “water loop”) or Air Distribution (type: “fan coil”). If the chiller has “water loop” distribution, a Water-Loop-to-Air Heat Pump must also be specified.

[407]

The sum of all FractionCoolLoadServed (across all HVAC systems) must be less than or equal to 1.

[408]

FanCoilWatts only required if chiller connected to fan coil.

Note

Chillers are modeled as central air conditioners with a SEER equivalent using the equation from ANSI/RESNET/ICC 301-2019.

Cooling Tower (Shared)

Each shared cooling tower (serving multiple dwelling units) is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/CoolingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [409]	See [410]		ID of attached zone
DistributionSystem	idref		See [411]	Yes		ID of attached distribution system
IsSharedSystem	boolean		true	Yes		Whether it serves multiple dwelling units
NumberofUnitsServed	integer		> 1	Yes		Number of dwelling units served
CoolingSystemType	string		cooling tower	Yes		Type of cooling system
CoolingSystemFuel	string		electricity	Yes		Fuel type
FractionCoolLoadServed	double	frac	>= 0, <= 1 [412]	Yes		Fraction of cooling load served
extension/SharedLoopWatts	double	W	>= 0	Yes		Pumping and fan power serving the system
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit

[409]

If AttachedToZone provided, it must reference a conditioned Zone.

[410]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[411]

HVACDistribution type must be Hydronic Distribution (type: “water loop”). A Water-Loop-to-Air Heat Pump must also be specified.

[412]

The sum of all FractionCoolLoadServed (across all HVAC systems) must be less than or equal to 1.

Note

Cooling towers w/ water loop heat pumps are modeled as central air conditioners with a SEER equivalent using the equation from ANSI/RESNET/ICC 301-2019.

HPXML Heat Pumps

The following heat pump types can be modeled:

• Air-to-Air Heat Pump

• Mini-Split Heat Pump

• Packaged Terminal Heat Pump

• Room Air Conditioner w/ Reverse Cycle

• Ground-to-Air Heat Pump

• Water-Loop-to-Air Heat Pump

Air-to-Air Heat Pump

Each air-to-air heat pump is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatPump.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [413]	See [414]		ID of attached zone
UnitLocation	string		See [415]	No	See [416]	Location of air handler
DistributionSystem	idref		See [417]	Yes		ID of attached distribution system
HeatPumpType	string		air-to-air	Yes		Type of heat pump
HeatPumpFuel	string		electricity	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [418]	Heating output capacity at 47F
HeatingCapacity17F	double	Btu/hr	>= 0, <= HeatingCapacity	No		Heating output capacity at 17F
CoolingCapacity	double	Btu/hr	>= 0	No	autosized [419]	Cooling output capacity
CompressorType	string		See [420]	Yes		Type of compressor
CompressorLockoutTemperature	double	F		No	See [421]	Minimum outdoor temperature for compressor operation
BackupType	string		See [422]	No	<none>	Type of backup heating
FractionHeatLoadServed	double	frac	>= 0, <= 1 [423]	Yes		Fraction of heating load served
FractionCoolLoadServed	double	frac	>= 0, <= 1 [424]	Yes		Fraction of cooling load served
AnnualCoolingEfficiency[Units="SEER2" or Units="SEER"]/Value	double	Btu/Wh	> 0	Yes		Rated cooling efficiency [425]
AnnualCoolingEfficiency[Units="EER2" or Units="EER"]/Value	double	Btu/Wh	> 0 [426]	No	See [427]	Rated cooling efficiency [428]
AnnualHeatingEfficiency[Units="HSPF2" or Units="HSPF"]/Value	double	Btu/Wh	> 0	Yes		Rated heating efficiency [429]
CoolingDetailedPerformanceData	element			No	<none>	Cooling detailed performance data [430]
HeatingDetailedPerformanceData	element			No	<none>	Heating detailed performance data [431]
extension/HeatingCapacityFraction17F	double	frac	>= 0, < 1	No	See [432]	Heating output capacity at 17F divided by heating output capacity at 47F [433]
extension/FanMotorType	string		See [434]	No	See [435]	Blower fan model type
extension/FanPowerWattsPerCFM	double	W/cfm	>= 0	No	See [436]	Blower fan efficiency at maximum fan speed
extension/HeatingDesignAirflowCFM	double	cfm	>= 0	No	See [437]	Blower fan heating design airflow rate
extension/CoolingDesignAirflowCFM	double	cfm	>= 0	No	See [438]	Blower fan cooling design airflow rate
extension/AirflowDefectRatio	double	frac	>= -0.9, <= 9	No	0.0	Deviation between design/installed airflow rates [439]
extension/ChargeDefectRatio	double	frac	>= -0.9, <= 9	No	0.0	Deviation between design/installed refrigerant charges [440]
extension/CrankcaseHeaterPowerWatts	double	W	>= 0	No	See [441]	Crankcase heater power
extension/PanHeaterPowerWatts	double	W	>= 0	No	150.0	Pan heater power
extension/PanHeaterControlType	string		See [442]	No	continuous	Pan heater control type [443]
extension/BackupHeatingActiveDuringDefrost	boolean			No	See [444]	Whether integrated backup heat is used during defrost [445]
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit
extension/EquipmentType	string		See [446]	No	split system	Equipment type only used for SEER/SEER2, EER/EER2, and HSPF/HSPF2 conversions

[413]

If AttachedToZone provided, it must reference a conditioned Zone.

[414]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[415]

UnitLocation choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, “other non-freezing space”, “roof deck”, “manufactured home belly”, or “unconditioned space”.

[416]

If UnitLocation not provided, defaults based on the distribution system:

- Air: supply duct location with the largest area, otherwise “conditioned space”

- DSE: “conditioned space” if FractionHeatLoadServed/FractionCoolLoadServed are 1, otherwise “unconditioned space”

[417]

HVACDistribution type must be Air Distribution (type: “regular velocity”) or Distribution System Efficiency (DSE).

[418]

Heating capacity autosized per ACCA Manual J/S based on heating design load (unless a different HeatPumpSizingMethodology was selected in HPXML HVAC Sizing Control).

[419]

Cooling capacity autosized per ACCA Manual J/S based on cooling design load (unless a different HeatPumpSizingMethodology was selected in HPXML HVAC Sizing Control).

[420]

CompressorType choices are “single stage”, “two stage”, or “variable speed”.

[421]

If neither CompressorLockoutTemperature nor BackupHeatingSwitchoverTemperature provided, CompressorLockoutTemperature defaults to 40F if fossil fuel backup otherwise -20F if CompressorType is “variable speed” otherwise 0F.

[422]

BackupType choices are “integrated” or “separate”. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature. Use “integrated” if the heat pump’s distribution system and blower fan power applies to the backup heating (e.g., built-in electric strip heat or an integrated backup furnace, i.e., a dual-fuel heat pump). Use “separate” if the backup system has its own distribution system (e.g., electric baseboard or a boiler). Additional backup inputs are described in Backup.

[423]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[424]

The sum of all FractionCoolLoadServed (across all HVAC systems) must be less than or equal to 1.

[425]

If SEER provided, converted to SEER2 using ANSI/RESNET/ICC 301-2022 Addendum C. For example, SEER2 = SEER * 0.95 if EquipmentType is “split system”.

[426]

In addition, EER2 must be <= SEER2; EER must be < SEER.

[427]

If neither EER2 nor EER provided, EER2 defaults to (0.73 * SEER2 + 1.47) for single stage, (0.63 * SEER2 + 2.34) for two stage, and (0.31 * SEER2 + 6.45) for variable speed, based on a regression analysis of ENERGY STAR products.

[428]

If EER provided, converted to EER2 using ANSI/RESNET/ICC 301-2022 Addendum C. For example, EER2 = EER * 0.95 if EquipmentType is “split system”.

[429]

If HSPF provided, converted to HSPF2 using ANSI/RESNET/ICC 301-2022 Addendum C. For example, HSPF2 = HSPF * 0.85 if EquipmentType is “split system”.

[430]

If CoolingDetailedPerformanceData is provided, see Detailed Cooling Performance Data.

[431]

If HeatingDetailedPerformanceData is provided, see Detailed Heating Performance Data.

[432]

If neither extension/HeatingCapacityFraction17F nor HeatingCapacity17F nor HeatingDetailedPerformanceData provided, heating capacity fraction at 17F defaults to 0.59 for single/two stage and 0.0329 * HSPF + 0.3996 for variable speed.

[433]

The extension/HeatingCapacityFraction17F input is a more flexible alternative to HeatingCapacity17F, as it can apply to autosized systems. Either input approach can be used, but not both.

[434]

FanMotorType choices are “PSC” (Permanent Split Capacitor) and “BPM” (Brushless Permanent Magnet).

[435]

If FanMotorType is not provided, defaults to “PSC” if CompressorType is “single stage”, else “BPM”.

[436]

If FanPowerWattsPerCFM not provided, defaults to 0.5 W/cfm if FanMotorType is “PSC”, else 0.375 W/cfm if FanMotorType is “BPM”.

[437]

If HeatingDesignAirflowCFM not provided, defaults to cfm/ton based on CoolingDesignAirflowCFM if provided, else 360 cfm/ton.

[438]

If CoolingDesignAirflowCFM not provided, defaults to cfm/ton based on HeatingDesignAirflowCFM if provided, else 360 cfm/ton.

[439]

AirflowDefectRatio is defined as (InstalledAirflow - DesignAirflow) / DesignAirflow; a value of zero means no airflow defect. See ANSI/RESNET/ACCA 310-2020 for more information.

[440]

ChargeDefectRatio is defined as (InstalledCharge - DesignCharge) / DesignCharge; a value of zero means no refrigerant charge defect. A non-zero charge defect should typically only be applied for systems that are charged on site, not for systems that have pre-charged line sets. See ANSI/RESNET/ACCA 310-2020 for more information.

[441]

If CrankcaseHeaterPowerWatts not provided, defaults to 10 W per ton of rated cooling capacity per RESNET HERS Addendum 82.

[442]

PanHeaterControlType choices are “continuous” or “defrost mode”.

[443]

If PanHeaterControlType is “continuous”, the pan heater will operate anytime the outdoor temperature is below 32F. If PanHeaterControlType is “defrost mode”, the pan heater will only operate when the heat pump is in defrost mode and the outdoor temperature is below 32F.

[444]

If BackupHeatingActiveDuringDefrost not provided, defaults to true if BackupType=”integrated”, otherwise false.

[445]

If BackupHeatingActiveDuringDefrost is “true”, backup heating system is assumed to perfectly temper the cooling delivered during defrost when its capacity is sufficient.

[446]

EquipmentType choices are “split system”, “packaged system”, “small duct high velocity system”, or “space constrained system”.

Mini-Split Heat Pump

Each mini-split heat pump is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatPump. Each HeatPump should represent a single outdoor unit, whether connected to one indoor head or multiple indoor heads.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [447]	See [448]		ID of attached zone
UnitLocation	string		See [449]	No	See [450]	Location of air handler
DistributionSystem	idref		See [451]	No		ID of attached distribution system, if present
HeatPumpType	string		mini-split	Yes		Type of heat pump
HeatPumpFuel	string		electricity	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [452]	Heating output capacity at 47F
HeatingCapacity17F	double	Btu/hr	>= 0, <= HeatingCapacity	No		Heating output capacity at 17F
CoolingCapacity	double	Btu/hr	>= 0	No	autosized [453]	Cooling output capacity
CompressorType	string		variable speed	Yes		Type of compressor
CompressorLockoutTemperature	double	F		No	See [454]	Minimum outdoor temperature for compressor operation
BackupType	string		See [455]	No	<none>	Type of backup heating
FractionHeatLoadServed	double	frac	>= 0, <= 1 [456]	Yes		Fraction of heating load served
FractionCoolLoadServed	double	frac	>= 0, <= 1 [457]	Yes		Fraction of cooling load served
AnnualCoolingEfficiency[Units="SEER2" or Units="SEER"]/Value	double	Btu/Wh	> 0	Yes		Rated cooling efficiency [458]
AnnualCoolingEfficiency[Units="EER2" or Units="EER"]/Value	double	Btu/Wh	> 0 [459]	No	See [460]	Rated cooling efficiency [461]
AnnualHeatingEfficiency[Units="HSPF2" or Units="HSPF"]/Value	double	Btu/Wh	> 0	Yes		Rated heating efficiency [462]
CoolingDetailedPerformanceData	element			No	<none>	Cooling detailed performance data [463]
HeatingDetailedPerformanceData	element			No	<none>	Heating detailed performance data [464]
extension/HeatingCapacityFraction17F	double	frac	>= 0, < 1	No	See [465]	Heating output capacity at 17F divided by heating output capacity at 47F [466]
extension/FanMotorType	string		See [467]	No	BPM	Blower fan model type
extension/FanPowerWattsPerCFM	double	W/cfm	>= 0	No	See [468]	Blower fan efficiency at maximum fan speed
extension/HeatingDesignAirflowCFM	double	cfm	>= 0	No	See [469]	Blower fan heating design airflow rate
extension/CoolingDesignAirflowCFM	double	cfm	>= 0	No	See [470]	Blower fan cooling design airflow rate
extension/AirflowDefectRatio	double	frac	>= -0.9, <= 9	No	0.0	Deviation between design/installed airflow rates [471]
extension/ChargeDefectRatio	double	frac	>= -0.9, <= 9	No	0.0	Deviation between design/installed refrigerant charges [472]
extension/CrankcaseHeaterPowerWatts	double	W	>= 0	No	See [473]	Crankcase heater power
extension/PanHeaterPowerWatts	double	W	>= 0	No	150.0	Pan heater power
extension/PanHeaterControlType	string		See [474]	No	continuous	Pan heater control type [475]
extension/BackupHeatingActiveDuringDefrost	boolean			No	See [476]	Whether integrated backup heat is used during defrost [477]
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[447]

If AttachedToZone provided, it must reference a conditioned Zone.

[448]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[449]

UnitLocation choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, “other non-freezing space”, “roof deck”, “manufactured home belly”, or “unconditioned space”.

[450]

If UnitLocation not provided, defaults based on the distribution system:

- Air: supply duct location with the largest area, otherwise “conditioned space”

- DSE: “conditioned space” if FractionHeatLoadServed/FractionCoolLoadServed are 1, otherwise “unconditioned space”

[451]

If DistributionSystem provided, HVACDistribution type must be Air Distribution (type: “regular velocity”) or Distribution System Efficiency (DSE).

[452]

Heating capacity autosized per ACCA Manual J/S based on heating design load (unless a different HeatPumpSizingMethodology was selected in HPXML HVAC Sizing Control).

[453]

Cooling capacity autosized per ACCA Manual J/S based on cooling design load (unless a different HeatPumpSizingMethodology was selected in HPXML HVAC Sizing Control).

[454]

If neither CompressorLockoutTemperature nor BackupHeatingSwitchoverTemperature provided, CompressorLockoutTemperature defaults to 40F if fossil fuel backup otherwise -20F.

[455]

BackupType choices are “integrated” or “separate”. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature. Use “integrated” if the heat pump’s distribution system and blower fan power applies to the backup heating (e.g., built-in electric strip heat or an integrated backup furnace, i.e., a dual-fuel heat pump). Use “separate” if the backup system has its own distribution system (e.g., electric baseboard or a boiler). Additional backup inputs are described in Backup.

[456]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[457]

The sum of all FractionCoolLoadServed (across all HVAC systems) must be less than or equal to 1.

[458]

If SEER provided, converted to SEER2 using ANSI/RESNET/ICC 301-2022 Addendum C, where SEER2 = SEER * 0.95 if ducted and SEER2 = SEER if ductless.

[459]

In addition, EER2 must be <= SEER2; EER must be < SEER.

[460]

If neither EER2 nor EER provided, EER2 defaults to (0.73 * SEER2 + 1.47) for single stage, (0.63 * SEER2 + 2.34) for two stage, and (0.31 * SEER2 + 6.45) for variable speed, based on a regression analysis of ENERGY STAR products.

[461]

If EER provided, converted to EER2 using ANSI/RESNET/ICC 301-2022 Addendum C, where EER2 = EER * 0.95 if ducted and EER2 = EER if ductless.

[462]

If HSPF provided, converted to HSPF2 using ANSI/RESNET/ICC 301-2022 Addendum C, where HSPF2 = HSPF * 0.85 if ducted and HSPF2 = HSPF * 0.90 if ductless.

[463]

If CoolingDetailedPerformanceData is provided, see Detailed Cooling Performance Data.

[464]

If HeatingDetailedPerformanceData is provided, see Detailed Heating Performance Data.

[465]

If neither extension/HeatingCapacityFraction17F nor HeatingCapacity17F nor HeatingDetailedPerformanceData provided, heating capacity fraction at 17F defaults to 0.0329 * HSPF + 0.3996.

[466]

The extension/HeatingCapacityFraction17F input is a more flexible alternative to HeatingCapacity17F, as it can apply to autosized systems. Either input approach can be used, but not both.

[467]

FanMotorType choices are “PSC” (Permanent Split Capacitor) and “BPM” (Brushless Permanent Magnet).

[468]

FanPowerWattsPerCFM defaults to 0.07 W/cfm for ductless systems and 0.18 W/cfm for ducted systems.

[469]

If HeatingDesignAirflowCFM not provided, defaults to cfm/ton based on CoolingDesignAirflowCFM if provided, else 360 cfm/ton.

[470]

If CoolingDesignAirflowCFM not provided, defaults to cfm/ton based on HeatingDesignAirflowCFM if provided, else 360 cfm/ton.

[471]

AirflowDefectRatio is defined as (InstalledAirflow - DesignAirflow) / DesignAirflow; a value of zero means no airflow defect. A non-zero airflow defect can only be applied for systems attached to a distribution system. See ANSI/RESNET/ACCA 310-2020 for more information.

[472]

ChargeDefectRatio is defined as (InstalledCharge - DesignCharge) / DesignCharge; a value of zero means no refrigerant charge defect. A non-zero charge defect should typically only be applied for systems that are charged on site, not for systems that have pre-charged line sets. See ANSI/RESNET/ACCA 310-2020 for more information.

[473]

If CrankcaseHeaterPowerWatts not provided, defaults to 10 W per ton of rated cooling capacity per RESNET HERS Addendum 82.

[474]

PanHeaterControlType choices are “continuous” or “defrost mode”.

[475]

If PanHeaterControlType is “continuous”, the pan heater will operate anytime the outdoor temperature is below 32F. If PanHeaterControlType is “defrost mode”, the pan heater will only operate when the heat pump is in defrost mode and the outdoor temperature is below 32F.

[476]

If BackupHeatingActiveDuringDefrost not provided, defaults to true if BackupType=”integrated” and there is an attached distribution system, otherwise false.

[477]

If BackupHeatingActiveDuringDefrost is “true”, backup heating system is assumed to perfectly temper the cooling delivered during defrost when its capacity is sufficient.

Packaged Terminal Heat Pump

Each packaged terminal heat pump is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatPump.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [478]	See [479]		ID of attached zone
DistributionSystem	idref		See [480]	No		ID of attached distribution system
HeatPumpType	string		packaged terminal heat pump	Yes		Type of heat pump
HeatPumpFuel	string		electricity	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [481]	Heating output capacity at 47F
HeatingCapacity17F	double	Btu/hr	>= 0, <= HeatingCapacity	No		Heating output capacity at 17F
CoolingCapacity	double	Btu/hr	>= 0	No	autosized [482]	Cooling output capacity
CompressorLockoutTemperature	double	F		No	See [483]	Minimum outdoor temperature for compressor operation
BackupType	string		See [484]	No	<none>	Type of backup heating
FractionHeatLoadServed	double	frac	>= 0, <= 1 [485]	Yes		Fraction of heating load served
FractionCoolLoadServed	double	frac	>= 0, <= 1 [486]	Yes		Fraction of cooling load served
AnnualCoolingEfficiency[Units="CEER" or Units="EER"]/Value	double	Btu/Wh	> 0	Yes		Rated cooling efficiency
AnnualHeatingEfficiency[Units="COP"]/Value	double	W/W	> 0	Yes		Rated heating efficiency
extension/HeatingCapacityFraction17F	double	frac	>= 0, < 1	No	See [487]	Heating output capacity at 17F divided by heating output capacity at 47F [488]
extension/CrankcaseHeaterPowerWatts	double	W	>= 0	No	0.0	Crankcase heater power
extension/BackupHeatingActiveDuringDefrost	boolean			No	false	Whether integrated backup heat is used during defrost [489]
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[478]

If AttachedToZone provided, it must reference a conditioned Zone.

[479]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[480]

DistributionSystem is only allowed to accommodate attaching a Central Fan Integrated Supply (CFIS) mechanical ventilation system to the ductless HVAC system. If DistributionSystem provided, HVACDistribution type must be Distribution System Efficiency (DSE) with a DSE of 1.

[481]

Heating capacity autosized per ACCA Manual J/S based on heating design load (unless a different HeatPumpSizingMethodology was selected in HPXML HVAC Sizing Control).

[482]

Cooling capacity autosized per ACCA Manual J/S based on cooling design load (unless a different HeatPumpSizingMethodology was selected in HPXML HVAC Sizing Control).

[483]

If neither CompressorLockoutTemperature nor BackupHeatingSwitchoverTemperature provided, CompressorLockoutTemperature defaults to 40F if fossil fuel backup otherwise 0F.

[484]

BackupType choices are “integrated” or “separate”. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature. Use “integrated” if the heat pump’s distribution system and blower fan power applies to the backup heating (e.g., built-in electric strip heat or an integrated backup furnace, i.e., a dual-fuel heat pump). Use “separate” if the backup system has its own distribution system (e.g., electric baseboard or a boiler). Additional backup inputs are described in Backup.

[485]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[486]

The sum of all FractionCoolLoadServed (across all HVAC systems) must be less than or equal to 1.

[487]

If neither extension/HeatingCapacityFraction17F nor HeatingCapacity17F provided, heating capacity fraction at 17F defaults to 0.59.

[488]

The extension/HeatingCapacityFraction17F input is a more flexible alternative to HeatingCapacity17F, as it can apply to autosized systems. Either input approach can be used, but not both.

[489]

If BackupHeatingActiveDuringDefrost is “true”, backup heating system is assumed to perfectly temper the cooling delivered during defrost when its capacity is sufficient.

Room Air Conditioner w/ Reverse Cycle

Each room air conditioner with reverse cycle is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatPump.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [490]	See [491]		ID of attached zone
DistributionSystem	idref		See [492]	No		ID of attached distribution system
HeatPumpType	string		room air conditioner with reverse cycle	Yes		Type of heat pump
HeatPumpFuel	string		electricity	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [493]	Heating output capacity at 47F
HeatingCapacity17F	double	Btu/hr	>= 0, <= HeatingCapacity	No		Heating output capacity at 17F
CoolingCapacity	double	Btu/hr	>= 0	No	autosized [494]	Cooling output capacity
CompressorLockoutTemperature	double	F		No	See [495]	Minimum outdoor temperature for compressor operation
BackupType	string		See [496]	No	<none>	Type of backup heating
FractionHeatLoadServed	double	frac	>= 0, <= 1 [497]	Yes		Fraction of heating load served
FractionCoolLoadServed	double	frac	>= 0, <= 1 [498]	Yes		Fraction of cooling load served
AnnualCoolingEfficiency[Units="CEER" or Units="EER"]/Value	double	Btu/Wh	> 0	Yes		Rated cooling efficiency
AnnualHeatingEfficiency[Units="COP"]/Value	double	W/W	> 0	Yes		Rated heating efficiency
extension/HeatingCapacityFraction17F	double	frac	>= 0, < 1	No	See [499]	Heating output capacity at 17F divided by heating output capacity 1t 47F [500]
extension/CrankcaseHeaterPowerWatts	double	W	>= 0	No	0.0	Crankcase heater power
extension/BackupHeatingActiveDuringDefrost	boolean			No	false	Whether integrated backup heat is used during defrost [501]
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[490]

If AttachedToZone provided, it must reference a conditioned Zone.

[491]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[492]

DistributionSystem is only allowed to accommodate attaching a Central Fan Integrated Supply (CFIS) mechanical ventilation system to the ductless HVAC system. If DistributionSystem provided, HVACDistribution type must be Distribution System Efficiency (DSE) with a DSE of 1.

[493]

Heating capacity autosized per ACCA Manual J/S based on heating design load (unless a different HeatPumpSizingMethodology was selected in HPXML HVAC Sizing Control).

[494]

Cooling capacity autosized per ACCA Manual J/S based on cooling design load (unless a different HeatPumpSizingMethodology was selected in HPXML HVAC Sizing Control).

[495]

If neither CompressorLockoutTemperature nor BackupHeatingSwitchoverTemperature provided, CompressorLockoutTemperature defaults to 40F if fossil fuel backup otherwise 0F.

[496]

BackupType choices are “integrated” or “separate”. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature. Use “integrated” if the heat pump’s distribution system and blower fan power applies to the backup heating (e.g., built-in electric strip heat or an integrated backup furnace, i.e., a dual-fuel heat pump). Use “separate” if the backup system has its own distribution system (e.g., electric baseboard or a boiler). Additional backup inputs are described in Backup.

[497]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[498]

The sum of all FractionCoolLoadServed (across all HVAC systems) must be less than or equal to 1.

[499]

If neither extension/HeatingCapacityFraction17F nor HeatingCapacity17F provided, heating capacity fraction at 17F defaults to 0.59.

[500]

The extension/HeatingCapacityFraction17F input is a more flexible alternative to HeatingCapacity17F, as it can apply to autosized systems. Either input approach can be used, but not both.

[501]

If BackupHeatingActiveDuringDefrost is “true”, backup heating system is assumed to perfectly temper the cooling delivered during defrost when its capacity is sufficient.

Ground-to-Air Heat Pump

Each ground-to-air heat pump is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatPump.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [502]	See [503]		ID of attached zone
UnitLocation	string		See [504]	No	See [505]	Location of air handler
DistributionSystem	idref		See [506]	Yes		ID of attached distribution system
IsSharedSystem	boolean			No	false	Whether it has a shared hydronic circulation loop [507]
HeatPumpType	string		ground-to-air	Yes		Type of heat pump
HeatPumpFuel	string		electricity	Yes		Fuel type
HeatingCapacity	double	Btu/hr	>= 0	No	autosized [508]	Heating output capacity
CoolingCapacity	double	Btu/hr	>= 0	No	autosized [509]	Cooling output capacity
CompressorType	string		See [510]	Yes		Type of compressor
BackupType	string		See [511]	No	<none>	Type of backup heating
FractionHeatLoadServed	double	frac	>= 0, <= 1 [512]	Yes		Fraction of heating load served
FractionCoolLoadServed	double	frac	>= 0, <= 1 [513]	Yes		Fraction of cooling load served
AnnualCoolingEfficiency[Units="EER"]/Value	double	Btu/Wh	> 0	Yes		Rated cooling efficiency
AnnualHeatingEfficiency[Units="COP"]/Value	double	W/W	> 0	Yes		Rated heating efficiency
NumberofUnitsServed	integer		> 0	See [514]		Number of dwelling units served
AttachedToGeothermalLoop	idref		See [515]	No [516]		ID of attached geothermal loop
extension/PumpPowerWattsPerTon	double	W/ton	>= 0	No	See [517]	Pump power [518]
extension/SharedLoopWatts	double	W	>= 0	See [519]		Shared pump power [520]
extension/FanMotorType	string		See [521]	No	See [522]	Blower fan model type
extension/FanPowerWattsPerCFM	double	W/cfm	>= 0	No	See [523]	Blower fan efficiency at maximum fan speed
extension/HeatingDesignAirflowCFM	double	cfm	>= 0	No	See [524]	Blower fan heating design airflow rate
extension/CoolingDesignAirflowCFM	double	cfm	>= 0	No	See [525]	Blower fan cooling design airflow rate
extension/AirflowDefectRatio	double	frac	>= -0.9, <= 9	No	0.0	Deviation between design/installed airflow rates [526]
extension/ChargeDefectRatio	double	frac	>= -0.9, <= 9	No	0.0	Deviation between design/installed refrigerant charges [527]
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[502]

If AttachedToZone provided, it must reference a conditioned Zone.

[503]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[504]

UnitLocation choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, “other non-freezing space”, “roof deck”, “manufactured home belly”, or “unconditioned space”.

[505]

If UnitLocation not provided, defaults based on the distribution system:

- Air: supply duct location with the largest area, otherwise “conditioned space”

- DSE: “conditioned space” if FractionHeatLoadServed/FractionCoolLoadServed are 1, otherwise “unconditioned space”

[506]

HVACDistribution type must be Air Distribution (type: “regular velocity”) or Distribution System Efficiency (DSE).

[507]

IsSharedSystem should be true if the SFA/MF building has multiple ground source heat pumps connected to a shared hydronic circulation loop.

[508]

Heating capacity autosized per ACCA Manual J/S based on heating design load.

[509]

Cooling capacity autosized per ACCA Manual J/S based on cooling design load.

[510]

CompressorType choices are “single stage”, “two stage”, or “variable speed”.

[511]

BackupType choices are “integrated” or “separate”. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature. Use “integrated” if the heat pump’s distribution system and blower fan power applies to the backup heating (e.g., built-in electric strip heat or an integrated backup furnace, i.e., a dual-fuel heat pump). Use “separate” if the backup system has its own distribution system (e.g., electric baseboard or a boiler). Additional backup inputs are described in Backup.

[512]

The sum of all FractionHeatLoadServed (across all HVAC systems) must be less than or equal to 1.

[513]

The sum of all FractionCoolLoadServed (across all HVAC systems) must be less than or equal to 1.

[514]

NumberofUnitsServed only required if IsSharedSystem is true, in which case it must be > 1.

[515]

AttachedToGeothermalLoop must reference a GeothermalLoop.

[516]

If AttachedToGeothermalLoop not provided, the ground-to-air heat pump will be automatically attached to a geothermal loop that is entirely defaulted.

[517]

If PumpPowerWattsPerTon not provided, defaults to 80 W/ton for a closed loop system.

[518]

Pump power is calculated using PumpPowerWattsPerTon and the cooling capacity in tons, unless the system only provides heating, in which case the heating capacity in tons is used instead. Any pump power that is shared by multiple dwelling units should be included in SharedLoopWatts, not PumpPowerWattsPerTon, so that shared loop pump power attributed to the dwelling unit is calculated.

[519]

SharedLoopWatts only required if IsSharedSystem is true.

[520]

Shared loop pump power attributed to the dwelling unit is calculated as SharedLoopWatts / NumberofUnitsServed.

[521]

FanMotorType choices are “PSC” (Permanent Split Capacitor) and “BPM” (Brushless Permanent Magnet).

[522]

If FanMotorType is not provided, defaults to “PSC” if COP <= 8.75/3.2, else “BPM”.

[523]

If FanPowerWattsPerCFM not provided, defaults to 0.5 W/cfm if FanMotorType is “PSC”, else 0.375 W/cfm if FanMotorType is “BPM”.

[524]

If HeatingDesignAirflowCFM not provided, defaults to cfm/ton based on CoolingDesignAirflowCFM if provided, else 360 cfm/ton.

[525]

If CoolingDesignAirflowCFM not provided, defaults to cfm/ton based on HeatingDesignAirflowCFM if provided, else 360 cfm/ton.

[526]

AirflowDefectRatio is defined as (InstalledAirflow - DesignAirflow) / DesignAirflow; a value of zero means no airflow defect. See ANSI/RESNET/ACCA 310-2020 for more information.

[527]

ChargeDefectRatio is defined as (InstalledCharge - DesignCharge) / DesignCharge; a value of zero means no refrigerant charge defect. A non-zero charge defect should typically only be applied for systems that are charged on site, not for systems that have pre-charged line sets. See ANSI/RESNET/ACCA 310-2020 for more information.

Water-Loop-to-Air Heat Pump

Each water-loop-to-air heat pump is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/HeatPump.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
AttachedToZone	idref		See [528]	See [529]		ID of attached zone
UnitLocation	string		See [530]	No	See [531]	Location of air handler
DistributionSystem	idref		See [532]	Yes		ID of attached distribution system
HeatPumpType	string		water-loop-to-air	Yes		Type of heat pump
HeatPumpFuel	string		electricity	Yes		Fuel type
HeatingCapacity	double	Btu/hr	> 0	No	autosized [533]	Heating output capacity
CoolingCapacity	double	Btu/hr	> 0	See [534]		Cooling output capacity
BackupType	string		See [535]	No	<none>	Type of backup heating
AnnualCoolingEfficiency[Units="EER"]/Value	double	Btu/Wh	> 0	See [536]		Rated cooling efficiency
AnnualHeatingEfficiency[Units="COP"]/Value	double	W/W	> 0	See [537]		Rated heating efficiency
extension/CoolingAutosizingFactor	double	frac	> 0	No	1.0	Cooling autosizing capacity multiplier
extension/HeatingAutosizingFactor	double	frac	> 0	No	1.0	Heating autosizing capacity multiplier
extension/CoolingAutosizingLimit	double	Btu/hr	> 0	No		Cooling autosizing capacity limit
extension/HeatingAutosizingLimit	double	Btu/hr	> 0	No		Heating autosizing capacity limit

[528]

If AttachedToZone provided, it must reference a conditioned Zone.

[529]

AttachedToZone only required if zone-level and space-level HVAC design load calculations are desired (see HPXML Zones/Spaces).

[530]

UnitLocation choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, “other non-freezing space”, “roof deck”, “manufactured home belly”, or “unconditioned space”.

[531]

If UnitLocation not provided, defaults based on the distribution system:

- Air: supply duct location with the largest area, otherwise “conditioned space”

- DSE: “conditioned space” if FractionHeatLoadServed/FractionCoolLoadServed are 1, otherwise “unconditioned space”

[532]

HVACDistribution type must be Air Distribution (type: “regular velocity”) or Distribution System Efficiency (DSE).

[533]

Heating capacity autosized per ACCA Manual J/S based on heating design load.

[534]

CoolingCapacity required if there is a shared chiller or cooling tower with water loop distribution.

[535]

BackupType choices are “integrated” or “separate”. Heat pump backup will only operate during colder temperatures when the heat pump runs out of heating capacity or is disabled due to a switchover/lockout temperature. Use “integrated” if the heat pump’s distribution system and blower fan power applies to the backup heating (e.g., built-in electric strip heat or an integrated backup furnace, i.e., a dual-fuel heat pump). Use “separate” if the backup system has its own distribution system (e.g., electric baseboard or a boiler). Additional backup inputs are described in Backup.

[536]

AnnualCoolingEfficiency required if there is a shared chiller or cooling tower with water loop distribution.

[537]

AnnualHeatingEfficiency required if there is a shared boiler with water loop distribution.

Note

If a water loop heat pump is specified, there must be at least one shared heating system (i.e., Boiler (Shared)) and/or one shared cooling system (i.e., Chiller (Shared) or Cooling Tower (Shared)) specified with water loop distribution.

Backup

If a backup type (“integrated” or “separate”) is provided, additional information is entered in HeatPump.

Element	Type	Units	Constraints	Required	Default	Notes
BackupHeatingSwitchoverTemperature or CompressorLockoutTemperature	double	F		No	See [538]	Minimum outdoor temperature for compressor operation
BackupHeatingSwitchoverTemperature or BackupHeatingLockoutTemperature	double	F	See [539]	No	See [540]	Maximum outdoor temperature for backup operation

[538]

If neither BackupHeatingSwitchoverTemperature nor CompressorLockoutTemperature provided, CompressorLockoutTemperature defaults as described above for individual heat pump types.

[539]

If both BackupHeatingLockoutTemperature and CompressorLockoutTemperature provided, BackupHeatingLockoutTemperature must be greater than or equal to CompressorLockoutTemperature.

[540]

If neither BackupHeatingSwitchoverTemperature nor BackupHeatingLockoutTemperature provided, BackupHeatingLockoutTemperature defaults to 40F for electric backup and 50F for fossil fuel backup.

Note

Provide BackupHeatingSwitchoverTemperature for a situation where there is a discrete outdoor temperature below which the heat pump stops operating and above which the backup heating system stops operating. Note that this control strategy has risk of the heating setpoint not being maintained (i.e., unmet hours) when the outdoor temperature is just above the switchover temperature, as the heat pump may not have sufficient capacity to meet the heating load and the backup is disabled.

Alternatively, provide A) CompressorLockoutTemperature to specify the outdoor temperature below which the heat pump stops operating and/or B) BackupHeatingLockoutTemperature to specify the outdoor temperature above which the heat pump backup system stops operating. If both are provided, the compressor and backup system can both operate between the two temperatures (e.g., simultaneous operation or cycling). If both are provided using the same temperature, it is equivalent to using BackupHeatingSwitchoverTemperature.

If a backup type of “integrated” is provided, additional information is entered in HeatPump.

Element	Type	Units	Constraints	Required	Default	Notes
BackupSystemFuel	string		See [541]	Yes		Integrated backup heating fuel type
BackupAnnualHeatingEfficiency[Units="Percent" or Units="AFUE"]/Value	double	frac	> 0, <= 1	Yes		Integrated backup heating efficiency
BackupHeatingCapacity	double	Btu/hr	>= 0	No	autosized [542]	Integrated backup heating output capacity
extension/BackupHeatingAutosizingFactor	double	frac	> 0	No	1.0	Backup Heating autosizing capacity multiplier
extension/BackupHeatingAutosizingLimit	double	Btu/hr	> 0	No		Backup Heating autosizing capacity limit

[541]

BackupSystemFuel choices are “electricity”, “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “wood”, or “wood pellets”.

[542]

Heating capacity autosized per ACCA Manual J/S based on heating design load. (The autosized capacity is not affected by the HeatPumpSizingMethodology selected in HPXML HVAC Sizing Control.)

If a backup type of “separate” is provided, additional information is entered in HeatPump.

Element	Type	Units	Constraints	Required	Default	Notes
BackupSystem	idref		See [543]	Yes		ID of separate backup heating system

[543]

BackupSystem must reference a HeatingSystem.

Note

Due to how the separate backup heating system is modeled in EnergyPlus, there are a few restrictions:

• The conditioned space cannot be partially heated (i.e., the sum of all FractionHeatLoadServed must be 1).

• There cannot be multiple backup heating systems.

HPXML HVAC Detailed Perf. Data

Some air-source HVAC system types allow detailed heating/cooling performance data to be provided using the CoolingDetailedPerformanceData and HeatingDetailedPerformanceData elements, as described above. One source of detailed performance data is NEEP’s Cold Climate Air Source Heat Pump List.

Detailed Cooling Performance Data

For air-source HVAC systems with detailed cooling performance data, performance datapoints are entered in CoolingDetailedPerformanceData/PerformanceDataPoint.

Element	Type	Units	Constraints	Required	Default	Notes
OutdoorTemperature	double	F	See [544]	Yes		Outdoor drybulb temperature
Capacity or CapacityFractionOfNominal	double	Btu/hr or frac	>= 0 [545]	Yes		Cooling capacity (or fraction) at the specified outdoor temperature
CapacityDescription	string		See [546]	Yes		Cooling capacity description
Efficiency[Units="COP"]/Value	double	W/W	> 0	Yes		Cooling efficiency at the specified outdoor temperature [547]

[544]

OutdoorTemperature choices are 82F, 95F, and one optional user-specified temperature greater than 95F. Datapoints at additional outdoor temperatures are not currently supported.

[545]

If Capacity is used, the nominal value for the 95F datapoint must match the CoolingCapacity input (if provided). If CapacityFractionOfNominal is used, the nominal value for the 95F datapoint must be 1.

[546]

CapacityDescription choices are “minimum”, “nominal”, and “maximum”. See the table below for the allowed combinations of CapacityDescription and OutdoorTemperature.

[547]

The COP should not include power required for defrost cycling or drain pan heater operation.

Allowed combinations of CapacityDescription and OutdoorTemperature for a given datapoints are:

Outdoor temperature	minimum [548]	nominal	maximum [549]
>95F	optional	optional	optional [550]
95F	required	required	required
82F	required	See [551]	required

[548]

Only two stage and variable speed equipment will use CapacityDescription=”minimum”.

[549]

Only variable speed equipment will use CapacityDescription=”maximum”.

[550]

For variable speed equipment, minimum/maximum datapoints must both be provided or both be omitted.

[551]

Nominal datapoint at 82F is require for single/two stage equipment and optional for variable speed equipment.

Note that when detailed cooling performance data is provided, some other inputs (like SEER) are ignored.

Detailed Heating Performance Data

For air-source HVAC systems with detailed heating performance data, performance datapoints are entered in HeatingDetailedPerformanceData/PerformanceDataPoint.

Element	Type	Units	Constraints	Required	Default	Notes
OutdoorTemperature	double	F	See [552]	Yes		Outdoor drybulb temperature
Capacity or CapacityFractionOfNominal	double	Btu/hr or frac	>= 0 [553]	Yes		Heating capacity (or fraction) at the specified outdoor temperature
CapacityDescription	string		See [554]	Yes		Heating capacity description
Efficiency[Units="COP"]/Value	double	W/W	> 0	Yes		Heating efficiency at the specified outdoor temperature [555]

[552]

OutdoorTemperature choices are 47F, 17F, 5F, and one optional user-specified temperature less than 5F. Datapoints at additional outdoor temperatures are not currently supported.

[553]

If Capacity is used, the nominal value for the 47F datapoint must match the HeatingCapacity input (if provided) and the nominal value for the 17F datapoint must match the HeatingCapacity17F input (if provided). If CapacityFractionOfNominal is used, the nominal value for the 95F datapoint must be 1.

[554]

CapacityDescription choices are “minimum”, “nominal”, and “maximum”. See the table below for the allowed combinations of CapacityDescription and OutdoorTemperature.

[555]

The COP should not include power required for defrost cycling or drain pan heater operation.

Allowed combinations of CapacityDescription and OutdoorTemperature for a given datapoints are:

Outdoor temperature	minimum [556]	nominal	maximum [557]
47F	required	required	required
17F	required	required	required
5F	required	optional	required
<5F	optional	optional	optional [558]

[556]

Only two stage and variable speed equipment will use CapacityDescription=”minimum”.

[557]

Only variable speed equipment will use CapacityDescription=”maximum”.

[558]

For variable speed equipment, minimum/maximum datapoints must both be provided or both be omitted.

Note that when detailed cooling performance data is provided, some other inputs (like HSPF) are ignored.

HPXML Geothermal Loops

Each geothermal loop is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACPlant/GeothermalLoop.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
LoopConfiguration	string		vertical	Yes		Geothermal loop configuration
LoopFlow	double	gal/min	> 0	No	See [559]	Water flow rate through the geothermal loop
BoreholesOrTrenches/Count	integer		>= 1, <= 10 [560]	No [561]	See [562]	Number of boreholes
BoreholesOrTrenches/Length	double	ft	>= 80, <= 500 [563]	No	See [564]	Length (i.e., average depth) of each borehole
BoreholesOrTrenches/Spacing	double	ft	> 0	No	16.4	Distance between boreholes
BoreholesOrTrenches/Diameter	double	in	> 0	No	5.0	Borehole diameter
Grout/Type or Grout/Conductivity	string or double	Btu/hr-ft-F	See [565] or > 0	No	standard	Grout type or conductivity [566]
Pipe/Type or Pipe/Conductivity	string or double	Btu/hr-ft-F	See [567] or > 0	No	standard	Pipe type or conductivity [568]
Pipe/Diameter	double	in	See [569]	No	1.25	Pipe diameter
Pipe/ShankSpacing	double	in	> 0	No	See [570]	Center-to-center distance between two branches of a vertical U-tube
extension/BorefieldConfiguration	string		See [571]	No	Rectangle	Configuration of boreholes

[559]

If LoopFlow not provided, is it autosized as 3 times the maximum of the ground source heat pump’s heating/cooling capacity in tons, with a minimum of 3 gal/min.

[560]

BoreholesOrTrenches/Count must be one of the following based on the borefield configuration:

- Rectangle: 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10

- Open Rectangle: 8 or 10

- C: 7 or 9

- L: 4, 5, 6, 7, 8, 9, or 10

- U: 7, 9, or 10

- Lopsided U: 6, 7, 8, 9, or 10

[561]

BoreholesOrTrenches/Count is only required if extension/BorefieldConfiguration is provided and not Rectangle.

[562]

If BoreholesOrTrenches/Count not provided, it is calculated as the required total length of the ground heat exchanger (calculated during sizing) divided by BoreholesOrTrenches/Length if BoreholesOrTrenches/Length is provided, otherwise autosized by assuming 1 for every ton of ground source heat pump cooling capacity (max of 10).

[563]

The minimum depth in the g-function library is 80 ft. The maximum realistic depth to be used in residential applications is 500 ft.

[564]

If BoreholesOrTrenches/Length not provided, it is calculated as the required total length of the ground heat exchanger (calculated during sizing) divided by the total number of boreholes.

[565]

Grout/Type choices are “standard” or “thermally enhanced”.

[566]

If Grout/Conductivity not provided, defaults based on Grout/Type:

- standard: 0.75 Btu/hr-ft-F

- thermally enhanced: 1.2 Btu/hr-ft-F

[567]

Pipe/Type choices are “standard” or “thermally enhanced”.

[568]

If Pipe/Conductivity not provided, defaults based on Pipe/Type:

- standard: 0.23 Btu/hr-ft-F

- thermally enhanced: 0.40 Btu/hr-ft-F

[569]

Pipe diameter must be either 0.75, 1.0, or 1.25.

[570]

ShankSpacing defaults to sum of U-tube spacing (assumed to be 0.9661 in) and pipe outer diameter, where pipe outer diameter is assumed to be:

- 0.75 in pipe: 1.050 in

- 1.0 in pipe: 1.315 in

- 1.25 in pipe: 1.660 in

[571]

extension/BorefieldConfiguration choices are “Rectangle”, “Open Rectangle”, “C”, “L”, “U”, or “Lopsided U”.

Note

For a given combination of extension/BorefieldConfiguration, BoreholesOrTrenches/Count, BoreholesOrTrenches/Spacing, BoreholesOrTrenches/Length, and BoreholesOrTrenches/Diameter g-function values are determined using the G-Function Library (from the Geothermal Data Repository).

HPXML HVAC Control

If any HVAC systems are specified, a single thermostat is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACControl.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
HeatingSeason	element			No	See [572]	Heating season
CoolingSeason	element			No	See [573]	Cooling season
extension/CeilingFanSetpointTempCoolingSeasonOffset	double	F	>= 0	No	0	Cooling setpoint temperature offset [574]

[572]

If HeatingSeason not provided, defaults to year-round.

[573]

If CoolingSeason not provided, defaults to year-round.

[574]

CeilingFanSetpointTempCoolingSeasonOffset should only be used if there are sufficient ceiling fans present to warrant a reduced cooling setpoint.

HPXML HVAC Seasons

If a heating and/or cooling season is defined, additional information is entered in HVACControl/HeatingSeason and/or HVACControl/CoolingSeason.

Element	Type	Units	Constraints	Required	Default	Notes
BeginMonth	integer		>= 1, <= 12	Yes		Begin month
BeginDayOfMonth	integer		>= 1, <= 31	Yes		Begin day
EndMonth	integer		>= 1, <= 12	Yes		End month
EndDayOfMonth	integer		>= 1, <= 31	Yes		End day

Warning

It is not possible to eliminate all HVAC energy use (e.g. crankcase/defrost energy) in EnergyPlus outside of an HVAC season.

HPXML HVAC Setpoints

Thermostat setpoints are additionally entered using either simple inputs, hourly inputs, or Detailed Schedule Inputs.

Simple Inputs

To define simple thermostat setpoints, additional information is entered in HVACControl.

Element	Type	Units	Constraints	Required	Default	Notes
SetpointTempHeatingSeason	double	F		No [575]	68	Heating setpoint temperature
SetpointTempCoolingSeason	double	F		No [576]	78	Cooling setpoint temperature

[575]

SetpointTempHeatingSeason only used if there is heating equipment.

[576]

SetpointTempCoolingSeason only used if there is cooling equipment.

If there is a heating temperature setback, additional information is entered in HVACControl.

Element	Type	Units	Constraints	Required	Default	Notes
SetbackTempHeatingSeason	double	F		Yes		Heating setback temperature
TotalSetbackHoursperWeekHeating	integer	hrs/week	> 0	Yes		Hours/week of heating temperature setback [577]
extension/SetbackStartHourHeating	integer		>= 0, <= 23	No	23 (11pm)	Daily setback start hour

[577]

TotalSetbackHoursperWeekHeating is converted to hrs/day and modeled as a temperature setback every day starting at SetbackStartHourHeating.

If there is a cooling temperature setup, additional information is entered in HVACControl.

Element	Type	Units	Constraints	Required	Default	Notes
SetupTempCoolingSeason	double	F		Yes		Cooling setup temperature
TotalSetupHoursperWeekCooling	integer	hrs/week	> 0	Yes		Hours/week of cooling temperature setup [578]
extension/SetupStartHourCooling	integer		>= 0, <= 23	No	9 (9am)	Daily setup start hour

[578]

TotalSetupHoursperWeekCooling is converted to hrs/day and modeled as a temperature setup every day starting at SetupStartHourCooling.

Hourly Inputs

To define hourly thermostat setpoints, additional information is entered in HVACControl.

Element	Type	Units	Constraints	Required	Default	Notes
extension/WeekdaySetpointTempsHeatingSeason	array	F		No [579]		24 comma-separated weekday heating setpoints
extension/WeekendSetpointTempsHeatingSeason	array	F		No		24 comma-separated weekend heating setpoints
extension/WeekdaySetpointTempsCoolingSeason	array	F		No [580]		24 comma-separated weekday cooling setpoints
extension/WeekendSetpointTempsCoolingSeason	array	F		No		24 comma-separated weekend cooling setpoints

[579]

WeekdaySetpointTempsHeatingSeason and WeekendSetpointTempsHeatingSeason only used if there is heating equipment.

[580]

WeekdaySetpointTempsCoolingSeason and WeekendSetpointTempsCoolingSeason only used if there is cooling equipment.

HPXML HVAC Distribution

The following distribution system types can be modeled:

• Air Distribution

• Hydronic Distribution

• Distribution System Efficiency (DSE)

Note

There can be at most one heating system and one cooling system attached to a distribution system. See HPXML Heating Systems, HPXML Cooling Systems, and HPXML Heat Pumps for information on which distribution system type is allowed for which HVAC system. Also note that some HVAC systems (e.g., room air conditioners) are not allowed to be attached to a distribution system.

Air Distribution

Each air distribution system is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACDistribution.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
DistributionSystemType/AirDistribution	element			Yes		Type of distribution system
DistributionSystemType/AirDistribution/AirDistributionType	string		See [581]	Yes		Type of air distribution
DistributionSystemType/AirDistribution/DuctLeakageMeasurement[DuctType="supply"]	element			See [582]		Supply duct leakage value
DistributionSystemType/AirDistribution/DuctLeakageMeasurement[DuctType="return"]	element			See [583]		Return duct leakage value
DistributionSystemType/AirDistribution/Ducts	element			No		Supply/return ducts; multiple are allowed [584]
DistributionSystemType/AirDistribution/NumberofReturnRegisters	integer		>= 0	No	See [585]	Number of return registers
DistributionSystemType/AirDistribution/extension/ManualJInputs/BlowerFanHeatBtuh	double	Btu/hr	>= 0	No	0	Blower fan heat for ACCA Manual J design loads [586]
DistributionSystemType/AirDistribution/extension/ManualJInputs/DefaultTableDuctLoad	element			No	<none>	Duct Factor Table inputs for ACCA Manual J design loads; multiple are allowed [587]
ConditionedFloorAreaServed	double	ft2	> 0	See [588]		Conditioned floor area served

[581]

AirDistributionType choices are “regular velocity”, “gravity”, or “fan coil” and are further restricted based on attached HVAC system type (e.g., only “regular velocity” or “gravity” for a furnace, only “fan coil” for a shared boiler, etc.).

[582]

Supply duct leakage required if AirDistributionType is “regular velocity” or “gravity” and optional if AirDistributionType is “fan coil”.

[583]

Return duct leakage required if AirDistributionType is “regular velocity” or “gravity” and optional if AirDistributionType is “fan coil”.

[584]

Provide a Ducts element for each supply duct and each return duct.

[585]

If NumberofReturnRegisters not provided and return ducts are present, defaults to one return register per conditioned floor per ASHRAE Standard 152, rounded up to the nearest integer if needed.

[586]

BlowerFanHeatBtuh should only be provided when calculating design loads for HVAC equipment whose performance data has not been adjusted for blower heat. When provided, it can be calculated according to Manual J Section 25 or the default of 1707 Btu/hr (500 W) can be used.

[587]

If one or more DefaultTableDuctLoad are provided, additional inputs are required as described below and are used with the ACCA Manual J Default Duct Factor Tables to calculate duct design loads. If not provided, duct design loads are calculated using distribution system efficiency (DSE) calculations from ASHRAE Standard 152.

[588]

ConditionedFloorAreaServed required only when duct surface area is defaulted (i.e., AirDistribution/Ducts are present without DuctSurfaceArea child elements).

Additional information is entered in each DuctLeakageMeasurement.

Element	Type	Units	Constraints	Required	Default	Notes
DuctLeakage/Units	string		See [589]	Yes		Duct leakage units
DuctLeakage/Value	double		>= 0 [590]	Yes		Duct leakage value [591]
DuctLeakage/TotalOrToOutside	string		See [592]	Yes		Type of duct leakage (outside conditioned space vs total)

[589]

Units choices are “CFM25”, “CFM50”, or “Percent”.

[590]

Value also must be < 1 if Units is Percent.

[591]

If the HVAC system has no return ducts (e.g., a ducted evaporative cooler), use zero for the Value.

[592]

TotalOrToOutside only choice is “to outside”.

Additional information is entered in each Ducts.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
DuctInsulationRValue and/or DuctEffectiveRValue	double	F-ft2-hr/Btu	>= 0	Yes		Duct R-value [593]
DuctBuriedInsulationLevel	string		See [594]	No	not buried	Duct buried insulation level [595]
DuctLocation	string		See [596]	No	See [597]	Duct location
FractionDuctArea and/or DuctSurfaceArea	double	frac or ft2	0-1 [598] or >= 0	See [599]	See [600]	Duct fraction/surface area in location
DuctShape and/or DuctFractionRectangular	string or double	n/a or frac	See [601] or >= 0, <= 1	No	See [602]	Duct shape (e.g., round vs rectangular)
extension/DuctSurfaceAreaMultiplier	double		>= 0	No	1.0	Duct surface area multiplier

[593]

It is recommended to provide DuctInsulationRValue and not DuctEffectiveRValue. DuctInsulationRValue represents the nominal insulation R-value and should not include interior/exterior air films (i.e., use 0 for an uninsulated duct). For ducts buried in insulation (i.e., DuctBuriedInsulationLevel is any value but “not buried”), DuctInsulationRValue should only represent any surrounding insulation duct wrap and not the entire attic insulation R-value. DuctEffectiveRValue is used in the actual duct heat transfer calculation, and should include all effects (i.e., interior/exterior air films, adjustments for presence of round ducts, and adjustments when buried in loose-fill attic insulation). When DuctEffectiveRValue is not provided, it is calculated from DuctInsulationRValue, DuctFractionRectangular, and DuctBuriedInsulationLevel based on ANSI/RESNET/ICC 301-2025 (not yet published) assuming round supply ducts are 6-in on average and round return ducts are 14-in on average.

[594]

DuctBuriedInsulationLevel choices are “not buried”, “partially buried”, “fully buried”, or “deeply buried”.

[595]

Whether the ducts are buried in, e.g., attic loose-fill insulation. Partially buried ducts have insulation that does not cover the top of the ducts. Fully buried ducts have insulation that just covers the top of the ducts. Deeply buried ducts have insulation that continues above the top of the ducts. See the Building America Solution Center for more information.

[596]

DuctLocation choices are “conditioned space”, “basement - conditioned”, “basement - unconditioned”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “outside”, “exterior wall”, “under slab”, “roof deck”, “other housing unit”, “other heated space”, “other multifamily buffer space”, “other non-freezing space”, or “manufactured home belly”. See HPXML Locations for descriptions.

[597]

If DuctLocation not provided, defaults to the first present space type: “basement - conditioned”, “basement - unconditioned”, “crawlspace - conditioned”, “crawlspace - vented”, “crawlspace - unvented”, “attic - vented”, “attic - unvented”, “garage”, or “conditioned space”. If NumberofConditionedFloorsAboveGrade > 1, secondary ducts will be located in “conditioned space”.

[598]

The sum of all FractionDuctArea must each equal to 1, both for the supply side and return side.

[599]

FractionDuctArea or DuctSurfaceArea are required if DuctLocation is provided. If both are provided, DuctSurfaceArea will be used in the model.

[600]

If neither DuctSurfaceArea nor FractionDuctArea provided, duct surface areas will be calculated based on ASHRAE Standard 152:

- Primary supply duct area: 0.27 * F_primary * ConditionedFloorAreaServed

- Secondary supply duct area: 0.27 * (1 - F_primary) * ConditionedFloorAreaServed

- Primary return duct area: b_r * F_primary * ConditionedFloorAreaServed

- Secondary return duct area: b_r * (1 - F_primary) * ConditionedFloorAreaServed

where F_primary is 1.0 if NumberofConditionedFloorsAboveGrade <= 1 else 0.75, and b_r is 0.05 * NumberofReturnRegisters (with a maximum value of 0.25).

If FractionDuctArea is provided, each duct surface area will be FractionDuctArea times total duct area, which is calculated using the sum of primary and secondary duct areas from the equations above.

[601]

DuctShape choices are “rectangular”, “round”, “oval”, or “other”.

[602]

If DuctFractionRectangular not provided, defaults to 1.0 if DuctShape is “rectangular” and 0.0 if DuctShape is “round” or “oval”. If DuctShape is “other” or not provided, DuctFractionRectangular defaults to 0.25 for supply ducts and 1.0 for return ducts.

If using Manual J default duct factor tables, additional information is entered in each DistributionSystemType/AirDistribution/extension/ManualJInputs/DefaultTableDuctLoad.

Element	Type	Units	Constraints	Required	Default	Notes
TableNumber	string		See [603]	Yes		Manual J Default Duct Factor Table number
LookupFloorArea	double	ft2	> 0	Yes		Lookup floor area value for the Manual J table [604]
LeakageLevel	string		See [605]	Yes		Leakage tightness value for the Manual J table
InsulationRValue	double	F-ft2-hr/Btu	>= 2	Yes		Insulation R-value for the Manual J table
SupplySurfaceArea or DSF	double	ft2 or frac	>= 0	No	DSF=1	Surface area or estimated fraction of supply ducts in unconditioned space
ReturnSurfaceArea or DSF	double	ft2 or frac	>= 0	No	DSF=1	Surface area or estimated fraction of return ducts in unconditioned space

[603]

TableNumber choices are “7A-R”, “7A-T”, “7B-R”, “7B-T”, “7A-AE”, “7B-AE”, “7C-AE”, “7C-R”, “7C-T”, “7D-R”, “7D-T”, “7E-R”, “7E-T”, “7F-R”, “7F-T”, “7G-R”, “7G-T”, “7H”, “7I”, “7D-AE”, “7J-1”, “7J-2”, “7K”, “7L”, “7M”, “7N”, “7O-1”, “7O-2”, “7O-3”, “7O-4”, “7P-1”, “7P-2”, “7P-3”, or “7P-4”.

[604]

The floor area lookup value should follow the Case 1, Case 2, Case 3, or Case 4 rules per ACCA Manual J Section 23-6.

[605]

LeakageLevel choices are “default not sealed”, “partially sealed”, “default sealed”, “notably sealed”, or “extremely sealed”.

Hydronic Distribution

Each hydronic distribution system is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACDistribution.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
DistributionSystemType/HydronicDistribution	element			Yes		Type of distribution system
DistributionSystemType/HydronicDistribution/HydronicDistributionType	string		See [606]	Yes		Type of hydronic distribution system
DistributionSystemType/HydronicDistribution/extension/ManualJInputs/HotWaterPipingBtuh	double	Btu/hr	>= 0	No	0	Piping load for ACCA Manual J design loads [607]

[606]

HydronicDistributionType choices are “radiator”, “baseboard”, “radiant floor”, “radiant ceiling”, or “water loop”.

[607]

HotWaterPipingBtuh should only be provided when hydronic distribution pipes run through unconditioned spaces. When provided, it can be calculated according to Manual J Section 26.

Distribution System Efficiency (DSE)

Warning

A simplified DSE model is provided for flexibility, but it is strongly recommended to use one of the other detailed distribution system types for better accuracy. The DSE input is simply applied to heating/cooling energy use for every hour of the year.

Each distribution system using DSE is entered as a /HPXML/Building/BuildingDetails/Systems/HVAC/HVACDistribution.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
DistributionSystemType/Other	string		DSE	Yes		Type of distribution system
AnnualHeatingDistributionSystemEfficiency	double	frac	> 0, <= 1	Yes		Seasonal distribution system efficiency for heating
AnnualCoolingDistributionSystemEfficiency	double	frac	> 0, <= 1	Yes		Seasonal distribution system efficiency for cooling

DSE values can be calculated using, e.g., ASHRAE Standard 152.

HPXML Mechanical Ventilation Fans

The following mechanical ventilation fan types that provide ventilation to the whole dwelling unit can be modeled:

• Exhaust Only

• Supply Only

• Balanced

• Heat Recovery Ventilator (HRV)

• Energy Recovery Ventilator (ERV)

• Central Fan Integrated Supply (CFIS)

Exhaust Only

Each exhaust only fan is entered as a /HPXML/Building/BuildingDetails/Systems/MechanicalVentilation/VentilationFans/VentilationFan.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units [608]
FanType	string		exhaust only	Yes		Type of ventilation system
RatedFlowRate or TestedFlowRate or CalculatedFlowRate or DeliveredVentilation	double	cfm	>= 0	No	See [609]	Flow rate
HoursInOperation	double	hrs/day	>= 0, <= 24	See [610]	24	Hours per day of operation
UsedForWholeBuildingVentilation	boolean		true	Yes		Ventilation fan use case [611]
FanPower	double	W	>= 0	No	See [612]	Fan power

[608]

Additional inputs for shared systems are described in Shared System.

[609]

If flow rate not provided, defaults to the required mechanical ventilation rate per ANSI/RESNET/ICC 301-2022:

Qfan = required mechanical ventilation rate (cfm) = ((Qtot^2 – 4*Qinf_eff^2 + 2*Qinf_eff*Qtot + Qinf_eff^2)^0.5 + Qtot - Qinf_eff) / 2

where

Qtot = total required ventilation rate (cfm) = 0.03 * ConditionedFloorArea + 7.5*(NumberofBedrooms + 1)

Qinf_eff = Qinf * Aext

Qinf = infiltration rate (cfm)

Aext = 1 if single-family detached or TypeOfInfiltrationLeakage is “unit exterior only”, otherwise ratio of SFA/MF exterior envelope surface area to total envelope surface area as described in HPXML Air Infiltration

OpenStudio-HPXML does not currently support defaulting flow rates for multiple mechanical ventilation fans.

[610]

HoursInOperation is optional unless the VentilationFan refers to the supplemental fan of a Central Fan Integrated Supply (CFIS) system, in which case it is not allowed because the runtime is automatically calculated for each hour to maintain the hourly target ventilation rate.

[611]

All other UsedFor… elements (i.e., UsedForLocalVentilation, UsedForSeasonalCoolingLoadReduction, UsedForGarageVentilation) must be omitted or false.

[612]

If FanPower not provided, defaults to 0.35 W/cfm based on ANSI/RESNET/ICC 301-2019.

Supply Only

Each supply only fan is entered as a /HPXML/Building/BuildingDetails/Systems/MechanicalVentilation/VentilationFans/VentilationFan.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units [613]
FanType	string		supply only	Yes		Type of ventilation system
RatedFlowRate or TestedFlowRate or CalculatedFlowRate or DeliveredVentilation	double	cfm	>= 0	No	See [614]	Flow rate
HoursInOperation	double	hrs/day	>= 0, <= 24	See [615]	24	Hours per day of operation
UsedForWholeBuildingVentilation	boolean		true	Yes		Ventilation fan use case [616]
FanPower	double	W	>= 0	No	See [617]	Fan power

[613]

Additional inputs for shared systems are described in Shared System.

[614]

If flow rate not provided, defaults to the required mechanical ventilation rate per ANSI/RESNET/ICC 301-2022:

Qfan = required mechanical ventilation rate (cfm) = ((Qtot^2 – 4*Qinf_eff^2 + 2*Qinf_eff*Qtot + Qinf_eff^2)^0.5 + Qtot - Qinf_eff) / 2

where

Qtot = total required ventilation rate (cfm) = 0.03 * ConditionedFloorArea + 7.5*(NumberofBedrooms + 1)

Qinf_eff = Qinf * Aext

Qinf = infiltration rate (cfm)

Aext = 1 if single-family detached or TypeOfInfiltrationLeakage is “unit exterior only”, otherwise ratio of SFA/MF exterior envelope surface area to total envelope surface area as described in HPXML Air Infiltration

OpenStudio-HPXML does not currently support defaulting flow rates for multiple mechanical ventilation fans.

[615]

HoursInOperation is optional unless the VentilationFan refers to the supplemental fan of a Central Fan Integrated Supply (CFIS) system, in which case it is not allowed because the runtime is automatically calculated for each hour to maintain the hourly target ventilation rate.

[616]

All other UsedFor… elements (i.e., UsedForLocalVentilation, UsedForSeasonalCoolingLoadReduction, UsedForGarageVentilation) must be omitted or false.

[617]

If FanPower not provided, defaults to 0.35 W/cfm based on ANSI/RESNET/ICC 301-2019.

Balanced

Each balanced (supply and exhaust) fan is entered as a /HPXML/Building/BuildingDetails/Systems/MechanicalVentilation/VentilationFans/VentilationFan.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units [618]
FanType	string		balanced	Yes		Type of ventilation system
RatedFlowRate or TestedFlowRate or CalculatedFlowRate or DeliveredVentilation	double	cfm	>= 0	No	See [619]	Flow rate
HoursInOperation	double	hrs/day	>= 0, <= 24	No	24	Hours per day of operation
UsedForWholeBuildingVentilation	boolean		true	Yes		Ventilation fan use case [620]
FanPower	double	W	>= 0	No	See [621]	Fan power

[618]

Additional inputs for shared systems are described in Shared System.

[619]

If flow rate not provided, defaults to the required mechanical ventilation rate per ANSI/RESNET/ICC 301-2022:

Qfan = required mechanical ventilation rate (cfm) = Qtot - Qinf_eff

where

Qtot = total required ventilation rate (cfm) = 0.03 * ConditionedFloorArea + 7.5*(NumberofBedrooms + 1)

Qinf_eff = Qinf * Aext

Qinf = infiltration rate (cfm)

Aext = 1 if single-family detached or TypeOfInfiltrationLeakage is “unit exterior only”, otherwise ratio of SFA/MF exterior envelope surface area to total envelope surface area as described in HPXML Air Infiltration

OpenStudio-HPXML does not currently support defaulting flow rates for multiple mechanical ventilation fans.

[620]

All other UsedFor… elements (i.e., UsedForLocalVentilation, UsedForSeasonalCoolingLoadReduction, UsedForGarageVentilation) must be omitted or false.

[621]

If FanPower not provided, defaults to 0.7 W/cfm based on ANSI/RESNET/ICC 301-2019.

Heat Recovery Ventilator (HRV)

Each heat recovery ventilator (HRV) is entered as a /HPXML/Building/BuildingDetails/Systems/MechanicalVentilation/VentilationFans/VentilationFan.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units [622]
FanType	string		heat recovery ventilator	Yes		Type of ventilation system
RatedFlowRate or TestedFlowRate or CalculatedFlowRate or DeliveredVentilation	double	cfm	>= 0	No	See [623]	Flow rate
HoursInOperation	double	hrs/day	>= 0, <= 24	No	24	Hours per day of operation
UsedForWholeBuildingVentilation	boolean		true	Yes		Ventilation fan use case [624]
AdjustedSensibleRecoveryEfficiency or SensibleRecoveryEfficiency	double	frac	> 0, <= 1	Yes		(Adjusted) Sensible recovery efficiency [625]
FanPower	double	W	>= 0	No	See [626]	Fan power

[622]

Additional inputs for shared systems are described in Shared System.

[623]

If flow rate not provided, defaults to the required mechanical ventilation rate per ANSI/RESNET/ICC 301-2022:

Qfan = required mechanical ventilation rate (cfm) = Qtot - Qinf_eff

where

Qtot = total required ventilation rate (cfm) = 0.03 * ConditionedFloorArea + 7.5*(NumberofBedrooms + 1)

Qinf_eff = Qinf * Aext

Qinf = infiltration rate (cfm)

Aext = 1 if single-family detached or TypeOfInfiltrationLeakage is “unit exterior only”, otherwise ratio of SFA/MF exterior envelope surface area to total envelope surface area as described in HPXML Air Infiltration

OpenStudio-HPXML does not currently support defaulting flow rates for multiple mechanical ventilation fans.

[624]

All other UsedFor… elements (i.e., UsedForLocalVentilation, UsedForSeasonalCoolingLoadReduction, UsedForGarageVentilation) must be omitted or false.

[625]

AdjustedSensibleRecoveryEfficiency (ASRE) is similar to SensibleRecoveryEfficiency (SRE), in that it reflects heating season performance, but excludes fan electric consumption. Since OpenStudio-HPXML separately models fan electric consumption, ASRE is a preferable input to SRE because it can be directly used in the energy model.

[626]

If FanPower not provided, defaults to 1.0 W/cfm based on ANSI/RESNET/ICC 301-2019.

Energy Recovery Ventilator (ERV)

Each energy recovery ventilator (ERV) is entered as a /HPXML/Building/BuildingDetails/Systems/MechanicalVentilation/VentilationFans/VentilationFan.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units [627]
FanType	string		energy recovery ventilator	Yes		Type of ventilation system
RatedFlowRate or TestedFlowRate or CalculatedFlowRate or DeliveredVentilation	double	cfm	>= 0	No	See [628]	Flow rate
HoursInOperation	double	hrs/day	>= 0, <= 24	No	24	Hours per day of operation
UsedForWholeBuildingVentilation	boolean		true	Yes		Ventilation fan use case [629]
AdjustedTotalRecoveryEfficiency or TotalRecoveryEfficiency	double	frac	> 0, <= 1	Yes		(Adjusted) Total recovery efficiency [630]
AdjustedSensibleRecoveryEfficiency or SensibleRecoveryEfficiency	double	frac	> 0, <= 1	Yes		(Adjusted) Sensible recovery efficiency [631]
FanPower	double	W	>= 0	No	See [632]	Fan power

[627]

Additional inputs for shared systems are described in Shared System.

[628]

If flow rate not provided, defaults to the required mechanical ventilation rate per ANSI/RESNET/ICC 301-2022:

Qfan = required mechanical ventilation rate (cfm) = Qtot - Qinf_eff

where

Qtot = total required ventilation rate (cfm) = 0.03 * ConditionedFloorArea + 7.5*(NumberofBedrooms + 1)

Qinf_eff = Qinf * Aext

Qinf = infiltration rate (cfm)

Aext = 1 if single-family detached or TypeOfInfiltrationLeakage is “unit exterior only”, otherwise ratio of SFA/MF exterior envelope surface area to total envelope surface area as described in HPXML Air Infiltration

OpenStudio-HPXML does not currently support defaulting flow rates for multiple mechanical ventilation fans.

[629]

All other UsedFor… elements (i.e., UsedForLocalVentilation, UsedForSeasonalCoolingLoadReduction, UsedForGarageVentilation) must be omitted or false.

[630]

AdjustedTotalRecoveryEfficiency (ATRE) is similar to TotalRecoveryEfficiency (TRE), in that it reflects cooling season performance, but excludes fan electric consumption. Since OpenStudio-HPXML separately models fan electric consumption, ATRE is a preferable input to TRE because it can be directly used in the energy model.

[631]

AdjustedSensibleRecoveryEfficiency (ASRE) is similar to SensibleRecoveryEfficiency (SRE), in that it reflects heating season performance, but excludes fan electric consumption. Since OpenStudio-HPXML separately models fan electric consumption, ASRE is a preferable input to SRE because it can be directly used in the energy model.

[632]

If FanPower not provided, defaults to 1.0 W/cfm based on ANSI/RESNET/ICC 301-2019.

Central Fan Integrated Supply (CFIS)

Each central fan integrated supply (CFIS) system is entered as a /HPXML/Building/BuildingDetails/Systems/MechanicalVentilation/VentilationFans/VentilationFan. A CFIS system is a supply ventilation system with an outdoor air inlet duct on the return side of a forced-air HVAC system.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
FanType	string		central fan integrated supply	Yes		Type of ventilation system
CFISControls/HasOutdoorAirControl	boolean			No	true	Presence of controls to block outdoor air when not ventilating [633]
CFISControls/AdditionalRuntimeOperatingMode	string		See [634]	No	air handler fan	How additional ventilation is provided (beyond HVAC system operation)
CFISControls/SupplementalFan	idref		See [635]	See [636]		The supplemental fan providing additional ventilation
CFISControls/extension/ControlType	string		See [637]	No	optimized	Primary air handler fan control strategy [638]
CFISControls/extension/SupplementalFanRunsWithAirHandlerFan	boolean			No [639]	false	Whether the supplemental fan also runs with the air handler fan [640]
RatedFlowRate or TestedFlowRate or CalculatedFlowRate or DeliveredVentilation	double	cfm	>= 0	No	See [641]	Flow rate [642]
HoursInOperation	double	hrs/day	>= 0, <= 24	false	8	Hours per day of operation [643]
UsedForWholeBuildingVentilation	boolean		true	Yes		Ventilation fan use case [644]
FanPower	double	W	>= 0	No [645]	See [646]	Blower fan power during ventilation only mode
AttachedToHVACDistributionSystem	idref		See [647]	Yes		ID of attached distribution system
extension/VentilationOnlyModeAirflowFraction	double	frac	>= 0, <= 1	No	1.0	Blower airflow rate fraction during ventilation only mode [648]

[633]

For example, an electronically-controlled mechanical damper, or an in-line fan that substantially blocks the flow when not running.

[634]

AdditionalRuntimeOperatingMode choices are “air handler fan”, “supplemental fan”, or “none”.

[635]

SupplementalFan must reference another VentilationFan where UsedForWholeBuildingVentilation=true, IsSharedSystem=false, and FanType=”exhaust only” or “supply only”.

[636]

SupplementalFan only required if AdditionalRuntimeOperatingMode is “supplemental fan”.

[637]

ControlType choices are “optimized” or “timer; “timer” is only allowed if AdditionalRuntimeOperatingMode=”air handler fan”.

[638]

If ControlType=”optimized”, ventilation operation is assumed to take advantage of normal HVAC operation as much as possible, resulting in the lowest possible air handler fan energy use. If ControlType=”timer”, ventilation operation occurs at a fixed interval and may fully, partially, or not coincide with HVAC operation for a given hour, resulting in higher air handler fan energy use.

[639]

SupplementalFanRunsWithAirHandlerFan only applies when AdditionalRuntimeOperatingMode=”supplemental fan”.

[640]

If SupplementalFanRunsWithAirHandlerFan is true, in addition to its normal operation, the supplemental fan will also run simultaneously with the air handler fan when outdoor air is being brought in. This is typically used with a supplemental exhaust fan to provide balanced (supply + exhaust) airflow, though any additional runtime where the supplemental fan runs by itself will still be imbalanced.

[641]

If flow rate not provided, defaults to the required mechanical ventilation rate per ANSI/RESNET/ICC 301-2022:

Qfan = required mechanical ventilation rate (cfm) = ((Qtot^2 – 4*Qinf_eff^2 + 2*Qinf_eff*Qtot + Qinf_eff^2)^0.5 + Qtot - Qinf_eff) / 2

where

Qtot = total required ventilation rate (cfm) = 0.03 * ConditionedFloorArea + 7.5*(NumberofBedrooms + 1)

Qinf_eff = Qinf * Aext

Qinf = infiltration rate (cfm)

Aext = 1 if single-family detached or TypeOfInfiltrationLeakage is “unit exterior only”, otherwise ratio of SFA/MF exterior envelope surface area to total envelope surface area as described in HPXML Air Infiltration

OpenStudio-HPXML does not currently support defaulting flow rates for multiple mechanical ventilation fans.

[642]

The flow rate should equal the amount of outdoor air provided to the distribution system, not the total airflow through the distribution system.

[643]

HoursInOperation is combined with the flow rate to form the hourly target ventilation rate (e.g., inputs of 90 cfm and 8 hrs/day produce an hourly target ventilation rate of 30 cfm). In addition, if AdditionalRuntimeOperatingMode=”air handler fan”, it defines the minutes per hour that the air handler must provide ventilation (e.g., 8 hrs/day is treated as 20 mins/hr).

[644]

All other UsedFor… elements (i.e., UsedForLocalVentilation, UsedForSeasonalCoolingLoadReduction, UsedForGarageVentilation) must be omitted or false.

[645]

FanPower only applies when AdditionalRuntimeOperatingMode=”air handler fan”, in which it determines the blower fan power during ventilation only mode.

[646]

If FanPower not provided, defaults to the attached HVAC system’s FanPowerWattsPerCFM multiplied by the maximum blower airflow rate and VentilationOnlyModeAirflowFraction.

[647]

HVACDistribution type cannot be Hydronic Distribution.

[648]

VentilationOnlyModeAirflowFraction only applies when AdditionalRuntimeOperatingMode=”air handler fan”. Defines the blower airflow rate when operating in ventilation only mode (i.e., not heating or cooling mode), as a fraction of the maximum blower airflow rate. This value will depend on whether the blower fan can operate at reduced airflow rates during ventilation only operation.

Shared System

If the specified system is a shared system (i.e., serving multiple dwelling units), additional information is entered in VentilationFan.

Element	Type	Units	Constraints	Required	Default	Notes
FractionRecirculation	double	frac	>= 0, <= 1	Yes		Fraction of supply air that is recirculated [649]
extension/InUnitFlowRate	double	cfm	>= 0 [650]	Yes		Flow rate delivered to the dwelling unit
extension/PreHeating	element			No	<none>	Supply air preconditioned by heating equipment? [651]
extension/PreCooling	element			No	<none>	Supply air preconditioned by cooling equipment? [652]

[649]

1-FractionRecirculation is assumed to be the fraction of supply air that is provided from outside. The value must be 0 for exhaust only systems.

[650]

InUnitFlowRate must also be < (RatedFlowRate or TestedFlowRate or CalculatedFlowRate or DeliveredVentilation).

[651]

PreHeating not allowed for exhaust only systems.

[652]

PreCooling not allowed for exhaust only systems.

If pre-heating is specified for the shared system, additional information is entered in extension/PreHeating.

Element	Type	Units	Constraints	Required	Default	Notes
Fuel	string		See [653]	Yes		Pre-heating equipment fuel type
AnnualHeatingEfficiency[Units="COP"]/Value	double	W/W	> 0	Yes		Pre-heating equipment annual COP
FractionVentilationHeatLoadServed	double	frac	>= 0, <= 1	Yes		Fraction of ventilation heating load served by pre-heating equipment

[653]

Fuel choices are “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “anthracite coal”, “electricity”, “wood”, or “wood pellets”.

If pre-cooling is specified for the shared system, additional information is entered in extension/PreCooling.

Element	Type	Units	Constraints	Required	Default	Notes
Fuel	string		See [654]	Yes		Pre-cooling equipment fuel type
AnnualCoolingEfficiency[Units="COP"]/Value	double	W/W	> 0	Yes		Pre-cooling equipment annual COP
FractionVentilationCoolLoadServed	double	frac	>= 0, <= 1	Yes		Fraction of ventilation cooling load served by pre-cooling equipment

[654]

Fuel only choice is “electricity”.

HPXML Local Ventilation Fans

Each fan that provides local ventilation (e.g., kitchen range fan or bathroom fan) is entered as a /HPXML/Building/BuildingDetails/Systems/MechanicalVentilation/VentilationFans/VentilationFan.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Count	integer		>= 0	No	See [655]	Number of identical fans
RatedFlowRate or TestedFlowRate or CalculatedFlowRate or DeliveredVentilation	double	cfm	>= 0	No	See [656]	Flow rate to outside [657]
HoursInOperation	double	hrs/day	>= 0, <= 24	No	See [658]	Hours per day of operation
FanLocation	string		See [659]	Yes		Location of the fan
UsedForLocalVentilation	boolean		true	Yes		Ventilation fan use case [660]
FanPower	double	W	>= 0	No	See [661]	Fan power
extension/StartHour	integer		>= 0, <= 23	No	See [662]	Daily start hour of operation

[655]

If Count not provided, defaults to 1 for kitchen fans and NumberofBathrooms for bath fans based on the 2010 BAHSP.

[656]

If flow rate not provided, defaults to 100 cfm for kitchen fans and 50 cfm for bath fans based on the 2010 BAHSP.

[657]

If the kitchen range fan is a recirculating fan, the flow rate should be described as zero.

[658]

If HoursInOperation not provided, defaults to 1 based on the 2010 BAHSP.

[659]

FanLocation choices are “kitchen” or “bath”.

[660]

All other UsedFor… elements (i.e., UsedForWholeBuildingVentilation, UsedForSeasonalCoolingLoadReduction, UsedForGarageVentilation) must be omitted or false.

[661]

If FanPower not provided, defaults to 0.3 W/cfm based on the 2010 BAHSP.

[662]

If StartHour not provided, defaults to 18 (6pm) for kitchen fans and 7 (7am) for bath fans based on the 2010 BAHSP.

HPXML Whole House Fans

Each whole house fan that provides cooling load reduction is entered as a /HPXML/Building/BuildingDetails/Systems/MechanicalVentilation/VentilationFans/VentilationFan.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
RatedFlowRate or TestedFlowRate or CalculatedFlowRate or DeliveredVentilation	double	cfm	>= 0	No	2*ConditionedFloorArea	Flow rate
UsedForSeasonalCoolingLoadReduction	boolean		true	Yes		Ventilation fan use case [663]
FanPower	double	W	>= 0	No	See [664]	Fan power

[663]

All other UsedFor… elements (i.e., UsedForWholeBuildingVentilation, UsedForLocalVentilation, UsedForGarageVentilation) must be omitted or false.

[664]

If FanPower not provided, defaults to 0.1 W/cfm.

Note

The whole house fan is assumed to operate during hours of favorable outdoor conditions and will take priority over operable windows (natural ventilation).

HPXML Water Heating Systems

The following water heater types can be modeled:

• Conventional Storage

• Tankless

• Heat Pump

• Combi Boiler w/ Storage

• Combi Boiler w/ Tankless Coil

If not entered, the simulation will not include water heating.

Conventional Storage

Each conventional storage water heater is entered as a /HPXML/Building/BuildingDetails/Systems/WaterHeating/WaterHeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
FuelType	string		See [665]	Yes		Fuel type
WaterHeaterType	string		storage water heater	Yes		Type of water heater
Location	string		See [666]	No	See [667]	Water heater location
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units or shared laundry room
TankVolume	double	gal	> 0	No	See [668]	Nominal tank volume
FractionDHWLoadServed	double	frac	>= 0, <= 1 [669]	Yes		Fraction of hot water load served [670]
HeatingCapacity	double	Btu/hr	> 0	No	See [671]	Heating capacity
UniformEnergyFactor or EnergyFactor	double	frac	< 1	Yes		EnergyGuide label rated efficiency
UsageBin or FirstHourRating	string or double	str or gal/hr	See [672] or > 0	No	See [673]	EnergyGuide label usage bin/first hour rating
RecoveryEfficiency	double	frac	> 0, <= 1 [674]	No	See [675]	Recovery efficiency
WaterHeaterInsulation/Jacket/JacketRValue	double	F-ft2-hr/Btu	>= 0	No	0	R-value of additional tank insulation wrap
HotWaterTemperature	double	F	> 0	No	125	Water heater setpoint [676]
UsesDesuperheater	boolean			No	false	Presence of desuperheater? [677]
extension/TankModelType	string		See [678]	No	mixed	Tank model type
extension/NumberofBedroomsServed	integer		> NumberofBedrooms	See [679]		Number of bedrooms served directly or indirectly

[665]

FuelType choices are “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “anthracite coal”, “electricity”, “wood”, or “wood pellets”.

[666]

Location choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[667]

If Location not provided, defaults to the first present space type:

- IECC zones 1-3: “garage”, “conditioned space”

- IECC zones 3-8, unknown: “basement - unconditioned”, “basement - conditioned”, “conditioned space”

[668]

If TankVolume not provided, defaults based on Table 8 in the 2014 BAHSP.

[669]

The sum of all FractionDHWLoadServed (across all WaterHeatingSystems) must equal to 1.

[670]

FractionDHWLoadServed represents only the fraction of the hot water load associated with the hot water fixtures. Additional hot water load from clothes washers/dishwashers will be automatically assigned to the appropriate water heater(s).

[671]

If HeatingCapacity not provided, defaults based on Table 8 in the 2014 BAHSP.

[672]

UsageBin choices are “very small”, “low”, “medium”, or “high”.

[673]

UsageBin/FirstHourRating are only used for water heaters that use UniformEnergyFactor. If neither UsageBin nor FirstHourRating provided, UsageBin defaults to “medium”. If FirstHourRating provided and UsageBin not provided, UsageBin is determined based on the FirstHourRating value.

[674]

RecoveryEfficiency must also be greater than the EnergyFactor (or UniformEnergyFactor).

[675]

If RecoveryEfficiency not provided, defaults to 0.98 if the fuel type is electric, otherwise based on a regression analysis of AHRI certified water heaters:

- Non-electric, EnergyFactor < 0.75: 0.252 * EnergyFactor + 0.608

- Non-electric, EnergyFactor >= 0.75: 0.561 * EnergyFactor + 0.439

[676]

The water heater setpoint can alternatively be defined using Detailed Schedule Inputs.

[677]

Additional desuperheater inputs are described in Desuperheater.

[678]

TankModelType choices are “mixed” or “stratified”. Only currently allowed if FuelType is “electricity”.

[679]

NumberofBedroomsServed only required if IsSharedSystem is true. Tank losses will be apportioned to the dwelling unit using its number of bedrooms divided by the total number of bedrooms served by the water heating system per ANSI/RESNET/ICC 301-2022. Each dwelling unit w/zero bedrooms should be counted as 1 bedroom – e.g., a value of 3 should be entered for a shared system serving 3 studio (zero bedroom) apartments.

Tankless

Each instantaneous tankless water heater is entered as a /HPXML/Building/BuildingDetails/Systems/WaterHeating/WaterHeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
FuelType	string		See [680]	Yes		Fuel type
WaterHeaterType	string		instantaneous water heater	Yes		Type of water heater
Location	string		See [681]	No	See [682]	Water heater location
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units or shared laundry room
PerformanceAdjustment	double	frac	>= 0, <= 1	No	See [683]	Multiplier on efficiency, typically to account for cycling
FractionDHWLoadServed	double	frac	>= 0, <= 1 [684]	Yes		Fraction of hot water load served [685]
UniformEnergyFactor or EnergyFactor	double	frac	< 1	Yes		EnergyGuide label rated efficiency
HotWaterTemperature	double	F	> 0	No	125	Water heater setpoint [686]
UsesDesuperheater	boolean			No	false	Presence of desuperheater? [687]
extension/NumberofBedroomsServed	integer		> NumberofBedrooms	See [688]		Number of bedrooms served directly or indirectly

[680]

FuelType choices are “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “anthracite coal”, “electricity”, “wood”, or “wood pellets”.

[681]

Location choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[682]

If Location not provided, defaults to the first present space type:

- IECC zones 1-3: “garage”, “conditioned space”

- IECC zones 3-8, unknown: “basement - unconditioned”, “basement - conditioned”, “conditioned space”

[683]

If PerformanceAdjustment not provided, defaults to 0.94 (UEF) or 0.92 (EF) based on ANSI/RESNET/ICC 301-2019.

[684]

The sum of all FractionDHWLoadServed (across all WaterHeatingSystems) must equal to 1.

[685]

FractionDHWLoadServed represents only the fraction of the hot water load associated with the hot water fixtures. Additional hot water load from clothes washers/dishwashers will be automatically assigned to the appropriate water heater(s).

[686]

The water heater setpoint can alternatively be defined using Detailed Schedule Inputs.

[687]

Additional desuperheater inputs are described in Desuperheater.

[688]

NumberofBedroomsServed only required if IsSharedSystem is true. Each dwelling unit w/zero bedrooms should be counted as 1 bedroom – e.g., a value of 3 should be entered for a shared system serving 3 studio (zero bedroom) apartments.

Heat Pump

Each heat pump water heater is entered as a /HPXML/Building/BuildingDetails/Systems/WaterHeating/WaterHeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
FuelType	string		electricity	Yes		Fuel type
WaterHeaterType	string		heat pump water heater	Yes		Type of water heater
Location	string		See [689]	No	See [690]	Water heater location
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units or shared laundry room
TankVolume	double	gal	> 0	No	See [691]	Nominal tank volume
FractionDHWLoadServed	double	frac	>= 0, <= 1 [692]	Yes		Fraction of hot water load served [693]
HeatingCapacity	double	Btu/hr	> 0	No	See [694]	Heating output capacity
BackupHeatingCapacity	double	Btu/hr	>= 0	No	15355 (4.5 kW)	Heating capacity of the electric resistance backup
UniformEnergyFactor or EnergyFactor	double	frac	> 1, <= 5	Yes		EnergyGuide label rated efficiency
HPWHOperatingMode	string		See [695]	No	hybrid/auto	Operating mode [696]
UsageBin or FirstHourRating	string or double	str or gal/hr	See [697] or > 0	No	See [698]	EnergyGuide label usage bin/first hour rating
WaterHeaterInsulation/Jacket/JacketRValue	double	F-ft2-hr/Btu	>= 0	No	0	R-value of additional tank insulation wrap
HotWaterTemperature	double	F	> 0	No	125	Water heater setpoint [699]
UsesDesuperheater	boolean			No	false	Presence of desuperheater? [700]
extension/NumberofBedroomsServed	integer		> NumberofBedrooms	See [701]		Number of bedrooms served directly or indirectly

[689]

Location choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[690]

If Location not provided, defaults to the first present space type:

- IECC zones 1-3: “garage”, “conditioned space”

- IECC zones 3-8, unknown: “basement - unconditioned”, “basement - conditioned”, “conditioned space”

[691]

If TankVolume not provided, defaults based on Table 8 in the 2014 BAHSP.

[692]

The sum of all FractionDHWLoadServed (across all WaterHeatingSystems) must equal to 1.

[693]

FractionDHWLoadServed represents only the fraction of the hot water load associated with the hot water fixtures. Additional hot water load from clothes washers/dishwashers will be automatically assigned to the appropriate water heater(s).

[694]

If HeatingCapacity not provided, defaults to 1706 Btu/hr (0.5 kW) multiplied by the heat pump COP.

[695]

HPWHOperatingMode choices are “hybrid/auto” or “heat pump only”.

[696]

The heat pump water heater operating mode can alternatively be defined using Detailed Schedule Inputs.

[697]

UsageBin choices are “very small”, “low”, “medium”, or “high”.

[698]

UsageBin/FirstHourRating are only used for water heaters that use UniformEnergyFactor. If neither UsageBin nor FirstHourRating provided, UsageBin defaults to “medium”. If FirstHourRating provided and UsageBin not provided, UsageBin is determined based on the FirstHourRating value.

[699]

The water heater setpoint can alternatively be defined using Detailed Schedule Inputs.

[700]

Additional desuperheater inputs are described in Desuperheater.

[701]

NumberofBedroomsServed only required if IsSharedSystem is true. Tank losses will be apportioned to the dwelling unit using its number of bedrooms divided by the total number of bedrooms served by the water heating system per ANSI/RESNET/ICC 301-2022. Each dwelling unit w/zero bedrooms should be counted as 1 bedroom – e.g., a value of 3 should be entered for a shared system serving 3 studio (zero bedroom) apartments.

Combi Boiler w/ Storage

Each combination boiler w/ storage tank (sometimes referred to as an indirect water heater) is entered as a /HPXML/Building/BuildingDetails/Systems/WaterHeating/WaterHeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
WaterHeaterType	string		space-heating boiler with storage tank	Yes		Type of water heater
Location	string		See [702]	No	See [703]	Water heater location
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units or shared laundry room
TankVolume	double	gal	> 0	No	See [704]	Nominal volume of the storage tank
FractionDHWLoadServed	double	frac	>= 0, <= 1 [705]	Yes		Fraction of hot water load served [706]
WaterHeaterInsulation/Jacket/JacketRValue	double	F-ft2-hr/Btu	>= 0	No	0	R-value of additional storage tank insulation wrap
StandbyLoss[Units="F/hr"]/Value	double	F/hr	> 0	No	See [707]	Storage tank standby losses
HotWaterTemperature	double	F	> 0	No	125	Water heater setpoint [708]
RelatedHVACSystem	idref		See [709]	Yes		ID of boiler
extension/NumberofBedroomsServed	integer		> NumberofBedrooms	See [710]		Number of bedrooms served directly or indirectly

[702]

Location choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[703]

If Location not provided, defaults to the first present space type:

- IECC zones 1-3: “garage”, “conditioned space”

- IECC zones 3-8, unknown: “basement - unconditioned”, “basement - conditioned”, “conditioned space”

[704]

If TankVolume not provided, defaults based on Table 8 in the 2014 BAHSP.

[705]

The sum of all FractionDHWLoadServed (across all WaterHeatingSystems) must equal to 1.

[706]

FractionDHWLoadServed represents only the fraction of the hot water load associated with the hot water fixtures. Additional hot water load from clothes washers/dishwashers will be automatically assigned to the appropriate water heater(s).

[707]

If StandbyLoss not provided, defaults based on a regression analysis of AHRI Directory of Certified Product Performance.

[708]

The water heater setpoint can alternatively be defined using Detailed Schedule Inputs.

[709]

RelatedHVACSystem must reference a HeatingSystem (Boiler).

[710]

NumberofBedroomsServed only required if IsSharedSystem is true. Tank losses will be apportioned to the dwelling unit using its number of bedrooms divided by the total number of bedrooms served by the water heating system per ANSI/RESNET/ICC 301-2022. Each dwelling unit w/zero bedrooms should be counted as 1 bedroom – e.g., a value of 3 should be entered for a shared system serving 3 studio (zero bedroom) apartments.

Combi Boiler w/ Tankless Coil

Each combination boiler w/ tankless coil is entered as a /HPXML/Building/BuildingDetails/Systems/WaterHeating/WaterHeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
WaterHeaterType	string		space-heating boiler with tankless coil	Yes		Type of water heater
Location	string		See [711]	No	See [712]	Water heater location
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units or shared laundry room
FractionDHWLoadServed	double	frac	>= 0, <= 1 [713]	Yes		Fraction of hot water load served [714]
HotWaterTemperature	double	F	> 0	No	125	Water heater setpoint [715]
RelatedHVACSystem	idref		See [716]	Yes		ID of boiler
extension/NumberofBedroomsServed	integer		> NumberofBedrooms	See [717]		Number of bedrooms served directly or indirectly

[711]

Location choices are “conditioned space”, “basement - unconditioned”, “basement - conditioned”, “attic - unvented”, “attic - vented”, “garage”, “crawlspace - unvented”, “crawlspace - vented”, “crawlspace - conditioned”, “other exterior”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[712]

If Location not provided, defaults to the first present space type:

- IECC zones 1-3: “garage”, “conditioned space”

- IECC zones 3-8, unknown: “basement - unconditioned”, “basement - conditioned”, “conditioned space”

[713]

The sum of all FractionDHWLoadServed (across all WaterHeatingSystems) must equal to 1.

[714]

FractionDHWLoadServed represents only the fraction of the hot water load associated with the hot water fixtures. Additional hot water load from clothes washers/dishwashers will be automatically assigned to the appropriate water heater(s).

[715]

The water heater setpoint can alternatively be defined using Detailed Schedule Inputs.

[716]

RelatedHVACSystem must reference a HeatingSystem (Boiler).

[717]

NumberofBedroomsServed only required if IsSharedSystem is true. Each dwelling unit w/zero bedrooms should be counted as 1 bedroom – e.g., a value of 3 should be entered for a shared system serving 3 studio (zero bedroom) apartments.

Desuperheater

If the water heater uses a desuperheater, additional information is entered in WaterHeatingSystem.

Element	Type	Units	Constraints	Required	Default	Notes
RelatedHVACSystem	idref		See [718]	Yes		ID of heat pump or air conditioner

[718]

RelatedHVACSystem must reference a HeatPump (air-to-air, mini-split, or ground-to-air) or CoolingSystem (central air conditioner or mini-split).

Warning

A desuperheater is currently not allowed if detailed water heater setpoint schedules are used.

A desuperheater is currently not allowed if GroundToAirHeatPumpModelType is “experimental”, see HPXML Simulation Control.

HPXML Hot Water Distribution

If any water heating systems are provided, a single hot water distribution system must be described:

• Standard

• Recirculation (In-Unit)

• Recirculation (Shared)

Hot water distribution systems are modeled according to the Energy Rating Rated Home in ANSI/RESNET/ICC 301-2019. If NumberofResidents is provided, then hot water distribution use from Equation 14 of Estimating Daily Domestic Hot-Water Use in North American Homes is substituted into the ANSI/RESNET/ICC 301 equations.

Note

In attached/multifamily buildings, only the hot water distribution system serving the dwelling unit should be defined. The hot water distribution associated with, e.g., a shared laundry room should not be defined.

Standard

A standard hot water distribution system is entered as a /HPXML/Building/BuildingDetails/Systems/WaterHeating/HotWaterDistribution.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
SystemType/Standard	element			Yes		Type of distribution system
SystemType/Standard/PipingLength	double	ft	> 0	No	See [719]	Length of piping [720]
PipeInsulation/PipeRValue	double	F-ft2-hr/Btu	>= 0	No	0.0	Pipe insulation R-value
DrainWaterHeatRecovery	element			No	<none>	Presence of drain water heat recovery device [721]

[719]

If PipingLength not provided, calculated using the following equation from ANSI/RESNET/ICC 301-2019:

PipeL = 2.0 * (CFA / NCfl)^0.5 + 10.0 * NCfl + 5.0 * Bsmnt

where

CFA = conditioned floor area [ft2],

NCfl = number of conditioned floor levels in the residence including conditioned basements,

Bsmnt = presence (1.0) or absence (0.0) of an unconditioned basement in the residence. If a building has both a conditioned and unconditioned basement on the same level, Bsmnt = 0 to avoid double counting.

[720]

PipingLength is the length of hot water piping from the hot water heater to the farthest hot water fixture, measured longitudinally from plans, assuming the hot water piping does not run diagonally, plus 10 feet of piping for each floor level, plus 5 feet of piping for unconditioned basements (if any).

[721]

Additional drain water heat recovery inputs are described in Drain Water Heat Recovery.

Recirculation (In-Unit)

An in-unit recirculation hot water distribution system is entered as a /HPXML/Building/BuildingDetails/Systems/WaterHeating/HotWaterDistribution.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
SystemType/Recirculation	element			Yes		Type of distribution system
SystemType/Recirculation/ControlType	string		See [722]	Yes		Recirculation control type
SystemType/Recirculation/RecirculationPipingLoopLength	double	ft	> 0	No	See [723]	Recirculation piping loop length [724]
SystemType/Recirculation/BranchPipingLength	double	ft	> 0	No	10	Branch piping length [725]
SystemType/Recirculation/PumpPower	double	W	>= 0	No	50 [726]	Recirculation pump power
PipeInsulation/PipeRValue	double	F-ft2-hr/Btu	>= 0	Yes		Pipe insulation R-value
DrainWaterHeatRecovery	element			No	<none>	Presence of drain water heat recovery device [727]
extension/RecirculationPumpWeekdayScheduleFractions	array			No	See [728]	24 comma-separated recirculation pump weekday fractions
extension/RecirculationPumpWeekendScheduleFractions	array			No		24 comma-separated recirculation pump weekend fractions
extension/RecirculationPumpMonthlyScheduleMultipliers	array			No	See [729]	12 comma-separated recirculation pump monthly multipliers

[722]

ControlType choices are “manual demand control”, “presence sensor demand control”, “temperature”, “timer”, or “no control”.

- manual demand control: The pump only runs when a user presses a button indicating they are about to use hot water.

- presence sensor demand control: The pump only runs when a sensor detects someone is present at the faucet.

- temperature: The pump runs based on monitoring temperature at some point in the system.

- timer: The pump is controlled by a timer.

- no control: The pump runs continuously.

[723]

If RecirculationPipingLoopLength not provided, calculated using the following equation from ANSI/RESNET/ICC 301-2019:

RecircPipeL = 2.0 * (2.0 * (CFA / NCfl)^0.5 + 10.0 * NCfl + 5.0 * Bsmnt) - 20.0

where

CFA = conditioned floor area [ft2],

NCfl = number of conditioned floor levels in the residence including conditioned basements,

Bsmnt = presence (1.0) or absence (0.0) of an unconditioned basement in the residence. If a building has both a conditioned and unconditioned basement on the same level, Bsmnt = 0 to avoid double counting.

[724]

RecirculationPipingLoopLength is the recirculation loop length including both supply and return sides, measured longitudinally from plans, assuming the hot water piping does not run diagonally, plus 20 feet of piping for each floor level greater than one plus 10 feet of piping for unconditioned basements.

[725]

BranchPipingLength is the length of the branch hot water piping from the recirculation loop to the farthest hot water fixture from the recirculation loop, measured longitudinally from plans, assuming the branch hot water piping does not run diagonally.

[726]

PumpPower default based on ANSI/RESNET/ICC 301-2019.

[727]

Additional drain water heat recovery inputs are described in Drain Water Heat Recovery.

[728]

If RecirculationPumpWeekdayScheduleFractions or RecirculationPumpWeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[729]

If RecirculationPumpMonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

Recirculation (Shared)

A shared recirculation hot water distribution system (serving multiple dwelling units) is entered as a /HPXML/Building/BuildingDetails/Systems/WaterHeating/HotWaterDistribution.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
SystemType/Standard	element			Yes		Type of distribution system
SystemType/Standard/PipingLength	double	ft	> 0	No	See [730]	Length of piping [731]
PipeInsulation/PipeRValue	double	F-ft2-hr/Btu	>= 0	No	0.0	Pipe insulation R-value
DrainWaterHeatRecovery	element			No	<none>	Presence of drain water heat recovery device [732]
extension/SharedRecirculation/NumberofBedroomsServed	integer		> NumberofBedrooms	Yes [733]		Number of bedrooms served
extension/SharedRecirculation/PumpPower	double	W	>= 0	No	220 [734]	Shared recirculation pump power
extension/SharedRecirculation/ControlType	string		See [735]	Yes		Shared recirculation control type
extension/RecirculationPumpWeekdayScheduleFractions	array			No	See [736]	24 comma-separated recirculation pump weekday fractions
extension/RecirculationPumpWeekendScheduleFractions	array			No		24 comma-separated recirculation pump weekend fractions
extension/RecirculationPumpMonthlyScheduleMultipliers	array			No	See [737]	12 comma-separated recirculation pump monthly multipliers

[730]

If PipingLength not provided, calculated using the following equation from ANSI/RESNET/ICC 301-2019:

PipeL = 2.0 * (CFA / NCfl)^0.5 + 10.0 * NCfl + 5.0 * Bsmnt

where

CFA = conditioned floor area [ft2],

NCfl = number of conditioned floor levels in the residence including conditioned basements,

Bsmnt = presence (1.0) or absence (0.0) of an unconditioned basement in the residence. If a building has both a conditioned and unconditioned basement on the same level, Bsmnt = 0 to avoid double counting.

[731]

PipingLength is the length of hot water piping from the shared recirculation loop to the farthest hot water fixture, measured longitudinally from plans, assuming the hot water piping does not run diagonally, plus 10 feet of piping for each floor level, plus 5 feet of piping for unconditioned basements (if any).

[732]

Additional drain water heat recovery inputs are described in Drain Water Heat Recovery.

[733]

Recirculation pump energy will be apportioned to the dwelling unit using its number of bedrooms divided by the total number of bedrooms served by the recirculation system per ANSI/RESNET/ICC 301-2022. Each dwelling unit w/zero bedrooms should be counted as 1 bedroom – e.g., a value of 3 should be entered for a shared system serving 3 studio (zero bedroom) apartments.

[734]

PumpPower default based on ANSI/RESNET/ICC 301-2019.

[735]

ControlType choices are “manual demand control”, “presence sensor demand control”, “temperature”, “timer”, or “no control”.

- manual demand control: The pump only runs when a user presses a button indicating they are about to use hot water.

- presence sensor demand control: The pump only runs when a sensor detects someone is present at the faucet.

- temperature: The pump runs based on monitoring temperature at some point in the system.

- timer: The pump is controlled by a timer.

- no control: The pump runs continuously.

[736]

If RecirculationPumpWeekdayScheduleFractions or RecirculationPumpWeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[737]

If RecirculationPumpMonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

Note

The shared recirculation system is required to have a standard in-unit hot water distribution system; stacked recirculation systems (i.e., shared recirculation loop plus an additional in-unit recirculation system) are more likely to indicate input errors than reflect an actual real-world scenario.

Drain Water Heat Recovery

If a drain water heat recovery (DWHR) device is specified, additional information is entered in DrainWaterHeatRecovery.

Element	Type	Units	Constraints	Required	Default	Notes
FacilitiesConnected	string		See [738]	Yes		Specifies which facilities are connected
EqualFlow	boolean			Yes		Specifies how the DHWR is configured [739]
Efficiency	double	frac	> 0, <= 1	Yes		Efficiency according to CSA 55.1

[738]

FacilitiesConnected choices are “one” or “all”. Use “one” if there are multiple showers and only one of them is connected to the DWHR. Use “all” if there is one shower and it’s connected to the DWHR or there are two or more showers connected to the DWHR.

[739]

EqualFlow should be true if the DWHR supplies pre-heated water to both the fixture cold water piping and the hot water heater potable supply piping.

Drain water heat recovery is modeled according to the Energy Rating Rated Home in ANSI/RESNET/ICC 301-2019.

HPXML Water Fixtures

Each water fixture is entered as a /HPXML/Building/BuildingDetails/Systems/WaterHeating/WaterFixture.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
WaterFixtureType	string		See [740]	Yes		Bathroom faucet or shower
Count	integer		> 0	No	See [741]	Number of similar water fixtures
LowFlow and/or FlowRate	boolean or double	gpm	> 0	Yes		Whether the fixture is considered low-flow and/or the flow rate [742]

[740]

WaterFixtureType choices are “shower head” or “faucet”. If the shower stall has multiple shower heads that operate simultaneously, combine them as a single entry.

[741]

A WaterFixture is considered low-flow if the fixture’s flow rate (gpm) is <= 2.0. Where a shower stall has multiple shower heads that operate simultaneously, use the sum of their flows.

[742]

If Count not provided for any water fixture, assumes that 60% of all fixtures are faucets and 40% are shower heads.

Additional information can be entered in /HPXML/Building/BuildingDetails/Systems/WaterHeating/.

Element	Type	Units	Constraints	Required	Default	Notes
extension/WaterFixturesUsageMultiplier	double		>= 0	No	1.0	Multiplier on hot water usage
extension/WaterFixturesWeekdayScheduleFractions	array			No	See [743]	24 comma-separated weekday fractions
extension/WaterFixturesWeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/WaterFixturesMonthlyScheduleMultipliers	array			No	See [744]	12 comma-separated monthly multipliers

[743]

If WaterFixturesWeekdayScheduleFractions or WaterFixturesWeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[744]

If WaterFixturesMonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

Water fixture hot water use is calculated per the Energy Rating Rated Home in ANSI/RESNET/ICC 301-2019, including RESNET HERS Addenda 81 and 90f. If NumberofResidents is provided, then water fixture use from Equation 14 of Estimating Daily Domestic Hot-Water Use in North American Homes is substituted into the ANSI/RESNET/ICC 301 equations.

HPXML Solar Thermal

A single solar hot water system can be described with either simple or detailed inputs.

• Simple Inputs

• Detailed Inputs

It is recommended to use detailed inputs and allow EnergyPlus to calculate the solar contribution to the hot water load; the simple inputs are provided if equivalent calculations are performed in another software tool.

Simple Inputs

A simple solar hot water system is entered as a /HPXML/Building/BuildingDetails/Systems/SolarThermal/SolarThermalSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
SystemType	string		hot water	Yes		Type of solar thermal system
SolarFraction	double	frac	> 0, <= 0.99	Yes		Solar fraction [745]
ConnectedTo	idref		See [746]	No [747]	<none>	Connected water heater

[745]

Portion of total conventional hot water heating load (delivered energy plus tank standby losses). Can be obtained from Directory of SRCC OG-300 Solar Water Heating System Ratings or NREL’s System Advisor Model or equivalent.

[746]

ConnectedTo must reference a WaterHeatingSystem. The referenced water heater cannot be a space-heating boiler nor attached to a desuperheater.

[747]

If ConnectedTo not provided, solar fraction will apply to all water heaters in the building.

Warning

The solar fraction will reduce the hot water load equally for every EnergyPlus timestep.

Detailed Inputs

A detailed solar hot water system is entered as a /HPXML/Building/BuildingDetails/Systems/SolarThermal/SolarThermalSystem.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
SystemType	string		hot water	Yes		Type of solar thermal system
CollectorArea	double	ft2	> 0	Yes		Area
CollectorLoopType	string		See [748]	Yes		Loop type
CollectorType	string		See [749]	Yes		System type
CollectorAzimuth or CollectorOrientation	integer or string	deg or direction	>= 0, <= 359 or See [750]	Yes		Direction panels face (clockwise from North)
CollectorTilt	double	deg	>= 0, <= 90	Yes		Tilt relative to horizontal
CollectorRatedOpticalEfficiency	double	frac	> 0, < 1	Yes		Rated optical efficiency [751]
CollectorRatedThermalLosses	double	Btu/hr-ft2-F	> 0	Yes		Rated thermal losses [752]
StorageVolume	double	gal	> 0	No	See [753]	Hot water storage volume
ConnectedTo	idref		See [754]	Yes		Connected water heater

[748]

CollectorLoopType choices are “liquid indirect”, “liquid direct”, or “passive thermosyphon”.

[749]

CollectorType choices are “single glazing black”, “double glazing black”, “evacuated tube”, or “integrated collector storage”.

[750]

CollectorOrientation choices are “northeast”, “east”, “southeast”, “south”, “southwest”, “west”, “northwest”, or “north”

[751]

CollectorRatedOpticalEfficiency is FRTA (y-intercept) from the Directory of SRCC OG-100 Certified Solar Collector Ratings.

[752]

CollectorRatedThermalLosses is FRUL (slope) from the Directory of SRCC OG-100 Certified Solar Collector Ratings.

[753]

If StorageVolume not provided, calculated as 1.5 gal/ft2 * CollectorArea.

[754]

ConnectedTo must reference a WaterHeatingSystem that is not of type space-heating boiler nor connected to a desuperheater.

HPXML Photovoltaics

Each solar electric photovoltaic (PV) system is entered as a /HPXML/Building/BuildingDetails/Systems/Photovoltaics/PVSystem. If not entered, the simulation will not include photovoltaics.

Many of the inputs are adopted from the PVWatts model.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units
Location	string		See [755]	No	roof	Mounting location
ModuleType	string		See [756]	No	standard	Type of module
Tracking	string		See [757]	No	fixed	Type of tracking
ArrayAzimuth or ArrayOrientation	integer or string	deg or direction	>= 0, <= 359 or See [758]	Yes		Direction panels face (clockwise from North)
ArrayTilt	double	deg	>= 0, <= 90	Yes		Tilt relative to horizontal
MaxPowerOutput	double	W	>= 0	Yes		Peak power
SystemLossesFraction or YearModulesManufactured	double or integer	frac or #	>= 0, <= 1 or > 1600	No	0.14 [759]	System losses [760]
AttachedToInverter	idref		See [761]	Yes		ID of attached inverter
extension/NumberofBedroomsServed	integer		> NumberofBedrooms	See [762]		Number of bedrooms served

[755]

Location choices are “ground” or “roof” mounted.

[756]

ModuleType choices are “standard”, “premium”, or “thin film”.

[757]

Tracking choices are “fixed”, “1-axis”, “1-axis backtracked”, or “2-axis”.

[758]

ArrayOrientation choices are “northeast”, “east”, “southeast”, “south”, “southwest”, “west”, “northwest”, or “north”

[759]

SystemLossesFraction default is derived from the PVWatts documentation, which breaks down the losses as follows. Note that the total loss (14%) is not the sum of the individual losses but is calculated by multiplying the reduction due to each loss.

- Soiling: 2%

- Shading: 3%

- Snow: 0%

- Mismatch: 2%

- Wiring: 2%

- Connections: 0.5%

- Light-induced degradation: 1.5%

- Nameplate rating: 1%

- Age: 0%

- Availability: 3%

If YearModulesManufactured provided but not SystemLossesFraction, calculated as:

SystemLossesFraction = 1.0 - (1.0 - 0.14) * (1.0 - (1.0 - 0.995^(CurrentYear - YearModulesManufactured))).

[760]

System losses due to soiling, shading, snow, mismatch, wiring, degradation, etc.

[761]

AttachedToInverter must reference an Inverter.

[762]

NumberofBedroomsServed only required if IsSharedSystem is true. PV generation will be apportioned to the dwelling unit using its number of bedrooms divided by the total number of bedrooms served by the PV system per ANSI/RESNET/ICC 301-2019.

HPXML Inverters

In addition, the PVSystem must be connected to an inverter that is entered as a /HPXML/Building/BuildingDetails/Systems/Photovoltaics/Inverter.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
InverterEfficiency	double	frac	> 0, <= 1 [763]	No	0.96	Inverter efficiency

[763]

For homes with multiple inverters, all InverterEfficiency elements must have the same value.

HPXML Electric Panels

A single electric panel can be entered as a /HPXML/Building/BuildingDetails/Systems/ElectricPanels/ElectricPanel.

Note: An electric panel is only used and subject to having default values applied when load calculation types are specified. See HPXML Electric Panel Calculations for more information about specifying electric panel load calculation types.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Voltage	string	V	See [764]	No	240	Service voltage
MaxCurrentRating	double	A	>= 0	No	200	Service max current rating
HeadroomSpaces	integer		>= 0	No	See [765]	Number of unoccupied breaker spaces
RatedTotalSpaces	integer		> 0	No	See [766]	Total number of breaker spaces
BranchCircuits	element			No	See [767]	Individual branch circuits
ServiceFeeders	element			No	See [768]	Individual service feeders

[764]

Voltage choices are “120” or “240”.

[765]

If HeadroomSpaces not provided, defaults to RatedTotalSpaces minus the sum of OccupiedSpaces for all BranchCircuits, or defaults to 3 if RatedTotalSpaces also not provided.

[766]

If RatedTotalSpaces not provided, defaults to HeadroomSpaces plus the sum of OccupiedSpaces for all BranchCircuits.

[767]

See Branch Circuits.

[768]

See Service Feeders.

See Electric Panel Outputs for descriptions of how breaker spaces and calculated loads appear in the output files.

Branch Circuits

Individual branch circuits entered in BranchCircuits/BranchCircuit.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Voltage	string	V	See [769]	No	See [770]	Voltage of the branch circuit
MaxCurrentRating	double	A	>= 0	No	See [771]	Max current rating of the branch circuit
OccupiedSpaces	double		See [772]	No	See [773]	Number of occupied breaker spaces
AttachedToComponent	idref			No		ID of attached component; multiple are allowed [774]

[769]

Voltage choices are “120” or “240”.

[770]

If Voltage not provided, defaults based on optional referenced components as follows:

- HeatingSystem[HeatingSystemFuel="electricity"]: 240

- CoolingSystem[CoolingSystemType!="room air conditioner"]: 240

- HeatPump[HeatPumpFuel="electricity"]: 240

- WaterHeatingSystem[FuelType="electricity"]: 240

- ClothesDryer[FuelType="electricity"]: 240

- CookingRange[FuelType="electricity"]: 240

- PermanentSpa/Pumps/Pump: 240

- PermanentSpa/Heater[Type="electric resistance" or "heat pump"]: 240

- Pool/Pumps/Pump: 240

- Pool/Heater[Type="electric resistance" or "heat pump"]: 240

- PlugLoad[PlugLoadType="well pump"]: 240

- PVSystem: 240

- Battery: 240

- Otherwise: 120

[771]

If MaxCurrentRating not provided, defaults based on Voltage as follows:

- 120: 15

- 240: 50

[772]

OccupiedSpaces choices are 0.0, 0.5, 1.0, or 2.0.

[773]

If OccupiedSpaces not provided, then Default Panels are used based on Voltage and properties of components referenced by AttachedToComponent. Components that are not attached to Service Feeders are assumed to occupy zero breaker spaces. If no corresponding Voltage is specified, the other Voltage classification will be used. Occupied breaker spaces will be recalculated based on the new Voltage classification. Occupied breaker spaces are calculated based on PowerRating, Voltage, and MaxCurrentRating as follows:

RequiredAmperage = PowerRating / Voltage

NumBranches = ceiling(RequiredAmperage / MaxCurrentRating)

NumBreakers = NumBranches * (Voltage / 120)

[774]

Provide a AttachedToComponent element for each referenced component.

Service Feeders

Individual service feeders entered in ServiceFeeders/ServiceFeeder.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
LoadType	string		See [775]	Yes		The type of the service feeder load
PowerRating	double	W	>= 0	No	See [776]	The power rating of the service feeder
IsNewLoad	boolean			No	false	Whether, in the context of NEC calculations, the load is new
AttachedToComponent	idref		See [777]	See [778]	See [779]	ID of attached component; multiple are allowed [780]

[775]

LoadType choices are “heating”, “cooling”, “hot water”, “clothes dryer”, “dishwasher”, “range/oven”, “mech vent”, “permanent spa heater”, “permanent spa pump”, “pool heater”, “pool pump”, “well pump”, “electric vehicle charging”, “lighting”, “kitchen”, “laundry”, and “other”.

[776]

If PowerRating not provided, then Default Panels are used based on Voltage and properties of components referenced by AttachedToComponent. If no corresponding Voltage is specified, the other Voltage classification will be used.

[777]

Depending on the LoadType, AttachedToComponent must reference:

- heating: HeatingSystem or HeatPump

- cooling: CoolingSystem or HeatPump

- hot water: WaterHeatingSystem

- clothes dryer: ClothesDryer

- dishwasher: Dishwasher

- range/oven: CookingRange

- mech vent: VentilationFan

- permanent spa heater: PermanentSpa/Heater

- permanent spa pump: PermanentSpa/Pumps/Pump

- pool heater: Pool/Heater

- pool pump: Pool/Pumps/Pump

- well pump: PlugLoad[PlugLoadType="well pump"]

- electric vehicle charging: PlugLoad[PlugLoadType="electric vehicle charging"] or ElectricVehicleCharger

[778]

Not allowed if LoadType is “lighting”, “kitchen”, “laundry”, or “other”; otherwise, required.

[779]

A service feeder is created for any electric component not already referenced by a service feeder. Service feeders for the following load types are always created if they don’t already exist:

- lighting

- kitchen

- laundry

- other

[780]

Provide a AttachedToComponent element for each referenced component.

Default Panels

If power rating or occupied breaker spaces are not provided, then they are defaulted. Default values may be based on power rating, voltage, amperage, component type, and other component properties such as number of bedrooms or bathrooms. They can also be found at HPXMLtoOpenStudio/resources/data/default_panels.csv.

Load Name	Voltage	Power Rating	Units	Breaker Spaces	Load Type	Notes
lighting	120	3	W/sqft	2	lighting	Multiplier for conditioned floor area to account for capacity impacts of general lighting.
kitchen	120	3000	W	2	kitchen	Two kitchen small appliance circuits at 1.5 kVA.
laundry	120	1500	W	1	laundry	One laundry circuit at 1.5 kVA.
ev_level	120	1650	W	1	electric vehicle charging	Level 1 - 120V EV charger.
ev_level	240	7680	W	2	electric vehicle charging	Level 2 - 240V EV charger.
wellpump_large	240	1119	W	2	well pump	Well pump capacity - 4 or larger bedroom home.
wellpump_small	240	746	W	2	well pump	Well pump capacity - 3 or fewer bedroom home.
poolpump	240	1491	W	2	pool pump	2 HP pool pump capacity.
poolheater	240	27000	W	6	pool heater	Electric resistance pool heater.
poolheater_hp	240	5100	W	2	pool heater	Heat pump pool heater.
spaheater	240	4000	W	2	permanent spa heater	Electric resistance hot tub heater.
spaheater_hp	240	1000	W	2	permanent spa heater	Heat pump hot tub heater.
spapump	240	1491	W	2	permanent spa pump	Hot tub pump.
dryer	240	5760	W	2	clothes dryer	Electric clothes dryer.
dryer_hp	120	996	W	1	clothes dryer	120V heat pump clothes dryer.
dryer_hp	240	860	W	2	clothes dryer	240V heat pump clothes dryer.
dishwasher	120	1200	W	1	dishwasher	Dishwasher.
rangeoven	120	1800	W	1	range/oven	120V range-oven.
rangeoven	240	12000	W	2	range/oven	240V range-oven.
rangeoven_induction	240	10000	W	2	range/oven	240V induction range-oven.
wh_tankless1	240	18000	W	4	hot water	Tankless water heater - one bathroom.
wh_tankless2	240	24000	W	4	hot water	Tankless water heater - two bathrooms.
wh_tankless3	240	36000	W	6	hot water	Tankless water heater - three or more bathrooms.
mechvent	120	3000	W	1	mech vent	Using autosized values for ventilation capacity unless unavailable.
other	120	373	W	1	other	Only assumes 1 garage door opener if a garage is present and does not account for other permanent appliances (e.g. garbage disposal).
wh_tank	240	auto	W	auto	hot water	Storage water heater.
wh_hp	120	auto	W	auto	hot water	120V heat pump water heater.
wh_hp	240	auto	W	auto	hot water	240V heat pump water heater.
heating	240	auto	W	auto	heating	Using autosize values for capacity of all heating.
cooling	240	auto	W	auto	cooling	Using autosize values for capacity of all cooling.

Mechanical ventilation loads may be assigned power ratings based on fan count and W (if available) otherwise 3000 W. Loads with power ratings of “auto” are calculated based on estimates for:

• input capacities (using regressions involving rated output capacities and efficiencies if direct expansion)

• blower fans (using fan W/cfm multiplied by airflow cfm)

• hydronic pumps (using electric auxiliary energy kWh/yr divided by 2.08)

Loads with occupied breaker spaces of “auto” vary based on calculated power ratings. Room air conditioners connected to a 120V branch circuit are assumed to occupy 0 breaker spaces.

HPXML Batteries

A single battery can be entered as a /HPXML/Building/BuildingDetails/Systems/Batteries/Battery. If not entered, the simulation will not include batteries.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units
Location	string		See [781]	No	See [782]	Location
BatteryType	string		See [783]	Yes		Battery type
NominalCapacity[Units="kWh" or Units="Ah"]/Value	double	kWh or Ah	>= 0	No	See [784]	Nominal (total) capacity
UsableCapacity[Units="kWh" or Units="Ah"]/Value	double	kWh or Ah	>= 0, < NominalCapacity	No	See [785]	Usable capacity
RatedPowerOutput	double	W	>= 0	No	See [786]	Power output under non-peak conditions
NominalVoltage	double	V	>= 0	No	50	Nominal voltage
RoundTripEfficiency	double	frac	> 0, <= 1	No	0.925	Round trip efficiency
extension/NumberofBedroomsServed	integer		> NumberofBedrooms	See [787]		Number of bedrooms served

[781]

Location choices are “conditioned space”, “basement - conditioned”, “basement - unconditioned”, “crawlspace - vented”, “crawlspace - unvented”, “crawlspace - conditioned”, “attic - vented”, “attic - unvented”, “garage”, or “outside”.

[782]

If Location not provided, defaults to “garage” if a garage is present, otherwise “outside”.

[783]

BatteryType only choice is “Li-ion”.

[784]

If NominalCapacity not provided, defaults to UsableCapacity / 0.9 if UsableCapacity provided, else (RatedPowerOutput / 1000) / 0.5 if RatedPowerOutput provided, else 10 kWh.

[785]

If UsableCapacity not provided, defaults to 0.9 * NominalCapacity.

[786]

If RatedPowerOutput not provided, defaults to 0.5 * NominalCapacity * 1000.

[787]

NumberofBedroomsServed only required if IsSharedSystem is true. Battery charging/discharging will be apportioned to the dwelling unit using its number of bedrooms divided by the total number of bedrooms served by the battery per ANSI/RESNET/ICC 301-2022 Addendum C.

Note

An unscheduled battery in a home with photovoltaics (PV) will be controlled using a simple control strategy designed to maximize on site consumption of energy. The battery will charge if PV production is greater than the building electrical load and the battery is below its maximum capacity, while the battery will discharge if the building electrical load is greater than PV production and the battery is above its minimum capacity.

A battery can alternatively be controlled using Detailed Schedule Inputs, where charging and discharging schedules are defined. Positive schedule values control timing and magnitude of charging storage. Negative schedule values control timing and magnitude of discharging storage. Simultaneous charging and discharging of the battery is not allowed. The round trip efficiency affects charging and discharging; the reported charging and discharging rates will be larger than the schedule value by an amount equal to the losses due to the round trip efficiency.

A battery in a home without PV or charging/discharging schedules is assumed to operate as backup and is not modeled.

HPXML Vehicles

A single battery electric vehicle can be entered in /HPXML/Building/BuildingDetails/Systems/Vehicles/Vehicle. All other vehicle types are currently not modeled. This provides detailed modeling of electric vehicles (batteries and charging/discharging) as an alternative to the simple EV charging in HPXML Plug Loads. If not entered, the simulation will not include a detailed electric vehicle model.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
VehicleType/BatteryElectricVehicle/Battery/BatteryType	string			No	Li-ion [788]	EV battery type
VehicleType/BatteryElectricVehicle/Battery/NominalCapacity[Units="kWh" or Units="Ah"]/Value	double	kWh or Ah	>= 0	No	See [789]	Nominal (total) capacity
VehicleType/BatteryElectricVehicle/Battery/UsableCapacity[Units="kWh" or Units="Ah"]/Value	double	kWh or Ah	>= 0, < NominalCapacity	No	See [790]	Usable capacity
VehicleType/BatteryElectricVehicle/Battery/NominalVoltage	double	V	>= 0	No		Nominal voltage
VehicleType/BatteryElectricVehicle/FractionChargedLocation[Location="Home"]/Percentage	double	frac	>= 0	No	See [791]	Fraction of EV charging energy provided by home charger
VehicleType/BatteryElectricVehicle/ConnectedCharger	idref		See [792]	No		ID of connected EV charger [793]
VehicleType/BatteryElectricVehicle/extension/WeekdayScheduleFractions	array			No	See [794]	24 comma-separated weekday fractions
VehicleType/BatteryElectricVehicle/extension/WeekendScheduleFractions	array			No		24 comma-separated weekday fractions
VehicleType/BatteryElectricVehicle/extension/MonthlyScheduleMultipliers	array			No	See [795]	12 comma-separated monthly multipliers
MilesDrivenPerYear	double	miles	>= 0	No	See [796]	Number of miles driven per year
HoursDrivenPerWeek	double	hours	>= 0	No	See [797]	Number of hours driven per week
FuelEconomyCombined[Units="kWh/mile" or Units="mile/kWh" or Units="mpge"]/Value	double		> 0	No	See [798]	The vehicle combined city and highway fuel economy

[788]

Only the “Li-ion” battery type is supported.

[789]

If NominalCapacity not provided, defaults to UsableCapacity / 0.8 if UsableCapacity provided, else 63 kWh per 2022 Autonomie release.

[790]

If UsableCapacity not provided, defaults to 0.8 * NominalCapacity.

[791]

If FractionChargedLocation[Location=”Home”] not provided, defaults to 0.8 per Levelized Cost of Charging Electric Vehicles in the United States.

[792]

ConnectedCharger must reference an ElectricVehicleCharger.

[793]

If a connected charger is not provided, home electric vehicle charging will not be modeled.

[794]

If WeekdayScheduleFractions or WeekendScheduleFractions are not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[795]

If MonthlyScheduleMultipliers are not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[796]

If MilesDrivenPerYear not provided, defaults to HoursDrivenPerWeek * 1227.5, else 10900 miles per 2017 National Household Travel Survey data.

[797]

If HoursDrivenPerWeek not provided, defaults to MilesDrivenPerYear / 1227.5, else 8.88 hours/week per 2017 National Household Travel Survey data.

[798]

If FuelEconomyCombined not provided, defaults to 0.22 kWh/mile per 2022 Autonomie release.

Note

Only EV charging that occurs at the home is modeled; charging that occurs at, e.g., work or public chargers is not captured.

If a PlugLoadType for “electric vehicle charging” is also specified, then a warning will be provided and the EV charging plug load will take precedence.

The effective discharge power is calculated using the vehicle FuelEconomyCombined, MilesDrivenPerYear, and the schedule. The discharge power is further influenced by the ambient temperature during simulation, and encompasses losses due to battery conditioning, vehicle conditioning, and charging losses.

HPXML Electric Vehicle Chargers

A single electric vehicle charger can be entered as a /HPXML/Building/BuildingDetails/Systems/ElectricVehicleChargers/ElectricVehicleCharger.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
ChargingLevel	integer		>= 1, <= 3	No	See [799]	Charger power level
ChargingPower	double	W	> 0	No	See [800]	Charger power output

[799]

If neither ChargingLevel nor ChargingPower provided, defaults to level 2.

[800]

If ChargingPower not provided, defaults to 1600 W if a level 1 charger, otherwise 5690 W per EV Watts Public Database.

HPXML Generators

Each generator that provides on-site power is entered as a /HPXML/Building/BuildingDetails/Systems/extension/Generators/Generator. If not entered, the simulation will not include generators.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
IsSharedSystem	boolean			No	false	Whether it serves multiple dwelling units
FuelType	string		See [801]	Yes		Fuel type
AnnualConsumptionkBtu	double	kBtu/yr	> 0	Yes		Annual fuel consumed
AnnualOutputkWh	double	kWh/yr	> 0 [802]	Yes		Annual electricity produced
NumberofBedroomsServed	integer		> NumberofBedrooms	See [803]		Number of bedrooms served

[801]

FuelType choices are “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “anthracite coal”, “wood”, or “wood pellets”.

[802]

AnnualOutputkWh must also be < AnnualConsumptionkBtu*3.412 (i.e., the generator must consume more energy than it produces).

[803]

NumberofBedroomsServed only required if IsSharedSystem is true. Annual consumption and annual production will be apportioned to the dwelling unit using its number of bedrooms divided by the total number of bedrooms served by the generator per ANSI/RESNET/ICC 301-2019.

Note

Generators will be modeled as operating continuously (24/7).

HPXML Appliances

Appliances entered in /HPXML/Building/BuildingDetails/Appliances.

HPXML Clothes Washer

A single clothes washer can be entered as a /HPXML/Building/BuildingDetails/Appliances/ClothesWasher. If not entered, the simulation will not include a clothes washer.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
IsSharedAppliance	boolean			No	false	Whether it serves multiple dwelling units [804]
Location	string		See [805]	No	conditioned space	Location
IntegratedModifiedEnergyFactor or ModifiedEnergyFactor	double	ft3/kWh/cyc	> 0	No	See [806]	Efficiency [807]
AttachedToWaterHeatingSystem or AttachedToHotWaterDistribution	idref		See [808]	See [809]		ID of attached water heater or distribution system
extension/UsageMultiplier	double		>= 0	No	1.0	Multiplier on energy & hot water usage
extension/WeekdayScheduleFractions	array			No	See [810]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [811]	12 comma-separated monthly multipliers

[804]

For example, a clothes washer in a shared laundry room of a MF building.

[805]

Location choices are “conditioned space”, “basement - conditioned”, “basement - unconditioned”, “garage”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[806]

If neither IntegratedModifiedEnergyFactor nor ModifiedEnergyFactor provided, the following default values representing a standard clothes washer from 2006 will be used: IntegratedModifiedEnergyFactor = 1.0, RatedAnnualkWh = 400, LabelElectricRate = 0.12, LabelGasRate = 1.09, LabelAnnualGasCost = 27.0, LabelUsage = 6, Capacity = 3.0.

[807]

If ModifiedEnergyFactor (MEF) provided instead of IntegratedModifiedEnergyFactor (IMEF), it will be converted using the Interpretation on ANSI/RESNET 301-2014 Clothes Washer IMEF: IMEF = (MEF - 0.503) / 0.95. IMEF may be found using the manufacturer’s data sheet, the California Energy Commission Appliance Database, the EPA ENERGY STAR website, or another reputable source.

[808]

AttachedToWaterHeatingSystem must reference a WaterHeatingSystem; AttachedToHotWaterDistribution must reference a HotWaterDistribution.

[809]

AttachedToWaterHeatingSystem (or AttachedToHotWaterDistribution) only required if IsSharedAppliance is true.

[810]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[811]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

If IntegratedModifiedEnergyFactor or ModifiedEnergyFactor is provided, a complete set of EnergyGuide label information is entered in ClothesWasher.

Element	Type	Units	Constraints	Required	Default	Notes
RatedAnnualkWh	double	kWh/yr	> 0	Yes		EnergyGuide label annual consumption
LabelElectricRate	double	$/kWh	> 0	Yes		EnergyGuide label electricity rate
LabelGasRate	double	$/therm	> 0	Yes		EnergyGuide label natural gas rate
LabelAnnualGasCost	double	$	> 0	Yes		EnergyGuide label annual gas cost
LabelUsage	double	cyc/wk	> 0	Yes		EnergyGuide label number of cycles
Capacity	double	ft3	> 0	Yes		Clothes washer volume

Clothes washer energy use and hot water use is calculated per the Energy Rating Rated Home in ANSI/RESNET/ICC 301-2019 Addendum A, including RESNET HERS Addenda 81 and 90f. If NumberofResidents is provided, then the number of cycles from Equation 1 of Estimating Daily Domestic Hot-Water Use in North American Homes is substituted into the ANSI/RESNET/ICC 301 equations.

HPXML Clothes Dryer

A single clothes dryer can be entered as a /HPXML/Building/BuildingDetails/Appliances/ClothesDryer. If not entered, the simulation will not include a clothes dryer.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
IsSharedAppliance	boolean			No	false	Whether it serves multiple dwelling units [812]
Location	string		See [813]	No	conditioned space	Location
FuelType	string		See [814]	Yes		Fuel type
DryingMethod	string		See [815]	No	conventional	The method of drying clothes
CombinedEnergyFactor or EnergyFactor	double	lb/kWh	> 0	No	See [816]	Efficiency [817]
Vented	boolean			No	See [818]	Whether dryer is vented
VentedFlowRate	double	cfm	>= 0	No	100 [819]	Exhaust flow rate during operation
extension/UsageMultiplier	double		>= 0	No	1.0	Multiplier on energy use
extension/WeekdayScheduleFractions	array			No	See [820]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [821]	12 comma-separated monthly multipliers

[812]

For example, a clothes dryer in a shared laundry room of a MF building.

[813]

Location choices are “conditioned space”, “basement - conditioned”, “basement - unconditioned”, “garage”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[814]

FuelType choices are “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “anthracite coal”, “electricity”, “wood”, or “wood pellets”.

[815]

DryingMethod choices are “conventional”, “condensing”, “heat pump”, or “other”.

[816]

If neither CombinedEnergyFactor nor EnergyFactor provided, the following default values representing a standard clothes dryer from 2006 will be used: CombinedEnergyFactor = 3.01.

[817]

If EnergyFactor (EF) provided instead of CombinedEnergyFactor (CEF), it will be converted using the following equation based on the Interpretation on ANSI/RESNET/ICC 301-2014 Clothes Dryer CEF: CEF = EF / 1.15. CEF may be found using the manufacturer’s data sheet, the California Energy Commission Appliance Database, the EPA ENERGY STAR website, or another reputable source.

[818]

If Vented not provided, defaults to false if DryingMethod is “condensing” or “heat pump”, otherwise true.

[819]

VentedFlowRate default based on the 2010 BAHSP.

[820]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[821]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

Clothes dryer energy use is calculated per the Energy Rating Rated Home in ANSI/RESNET/ICC 301-2019 Addendum A, including RESNET HERS Addenda 81 and 90f.

HPXML Dishwasher

A single dishwasher can be entered as a /HPXML/Building/BuildingDetails/Appliances/Dishwasher. If not entered, the simulation will not include a dishwasher.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
IsSharedAppliance	boolean			No	false	Whether it serves multiple dwelling units [822]
Location	string		See [823]	No	conditioned space	Location
RatedAnnualkWh or EnergyFactor	double	kWh/yr or #	> 0	No	See [824]	EnergyGuide label consumption/efficiency [825]
AttachedToWaterHeatingSystem or AttachedToHotWaterDistribution	idref		See [826]	See [827]		ID of attached water heater or distribution system
extension/UsageMultiplier	double		>= 0	No	1.0	Multiplier on energy & hot water usage
extension/WeekdayScheduleFractions	array			No	See [828]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [829]	12 comma-separated monthly multipliers

[822]

For example, a dishwasher in a shared mechanical room of a MF building.

[823]

Location choices are “conditioned space”, “basement - conditioned”, “basement - unconditioned”, “garage”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[824]

If neither RatedAnnualkWh nor EnergyFactor provided, the following default values representing a standard dishwasher from 2006 will be used: RatedAnnualkWh = 467, LabelElectricRate = 0.12, LabelGasRate = 1.09, LabelAnnualGasCost = 33.12, LabelUsage = 4, PlaceSettingCapacity = 12.

[825]

If EnergyFactor (EF) provided instead of RatedAnnualkWh, it will be converted using the following equation based on ANSI/RESNET/ICC 301-2014: RatedAnnualkWh = 215.0 / EF.

[826]

AttachedToWaterHeatingSystem must reference a WaterHeatingSystem; AttachedToHotWaterDistribution must reference a HotWaterDistribution.

[827]

AttachedToWaterHeatingSystem (or AttachedToHotWaterDistribution) only required if IsSharedAppliance is true.

[828]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[829]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

If the RatedAnnualkWh or EnergyFactor is provided, a complete set of EnergyGuide label information is entered in Dishwasher.

Element	Type	Units	Constraints	Required	Default	Notes
PlaceSettingCapacity	integer	#	> 0	Yes		Number of place settings
LabelElectricRate	double	$/kWh	> 0	Yes		EnergyGuide label electricity rate
LabelGasRate	double	$/therm	> 0	Yes		EnergyGuide label natural gas rate
LabelAnnualGasCost	double	$	> 0	Yes		EnergyGuide label annual gas cost
LabelUsage	double	cyc/wk	> 0	Yes		EnergyGuide label number of cycles

Dishwasher energy use and hot water use is calculated per the Energy Rating Rated Home in ANSI/RESNET/ICC 301-2019 Addendum A, including RESNET HERS Addenda 81 and 90f. If NumberofResidents is provided, then the number of cycles from Equation 3 of Estimating Daily Domestic Hot-Water Use in North American Homes is substituted into the ANSI/RESNET/ICC 301 equations.

HPXML Refrigerators

Each refrigerator can be entered as a /HPXML/Building/BuildingDetails/Appliances/Refrigerator. If not entered, the simulation will not include a refrigerator.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Location	string		See [830]	No	See [831]	Location
RatedAnnualkWh	double	kWh/yr	> 0	No	See [832]	Annual consumption
PrimaryIndicator	boolean			See [833]		Primary refrigerator?
extension/UsageMultiplier	double		>= 0	No	1.0	Multiplier on energy use
extension/WeekdayScheduleFractions	array		See [834]	No	See [835]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [836]	12 comma-separated monthly multipliers
extension/ConstantScheduleCoefficients	array			No	See [837]	24 comma-separated constant coefficients
extension/TemperatureScheduleCoefficients	array			No	See [838]	24 comma-separated temperature coefficients

[830]

Location choices are “conditioned space”, “basement - conditioned”, “basement - unconditioned”, “garage”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[831]

If Location not provided and is the primary refrigerator, defaults to “conditioned space”. If Location not provided and is a secondary refrigerator, defaults to the first present space type: “garage”, “basement - unconditioned”, “basement - conditioned”, or “conditioned space”.

[832]

If RatedAnnualkWh not provided, it will be defaulted to represent a standard refrigerator from 2006 using the following equation based on ANSI/RESNET/ICC 301-2019: RatedAnnualkWh = 637.0 + 18.0 * NumberofBedrooms.

[833]

If multiple refrigerators are specified, there must be exactly one refrigerator described with PrimaryIndicator=true.

[834]

Either schedule fraction inputs (WeekdayScheduleFractions/WeekendScheduleFractions/MonthlyScheduleMultipliers) or schedule coefficient inputs (ConstantScheduleCoefficients/TemperatureScheduleCoefficients) may be used, but not both.

[835]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs or schedule coefficients not used), then Default Schedules are used.

[836]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs or schedule coefficients not used), then Default Schedules are used.

[837]

If ConstantScheduleCoefficients not provided (and Detailed Schedule Inputs or schedule fractions not used), then Default Schedules are used.

[838]

If TemperatureScheduleCoefficients not provided (and Detailed Schedule Inputs or schedule fractions not used), then Default Schedules are used.

Note

Refrigerator energy use is affected by its ambient temperature when ConstantScheduleCoefficients and TemperatureScheduleCoefficients are used, in which case hourly energy for refrigerators is determined following Equation 4.2-X2 of ANSI/RESNET/ICC 301-2022 Addendum C:

((RatedAnnualkWh / 8760) * (ConstantScheduleCoefficients[hr] + TemperatureScheduleCoefficients[hr] * T_space)

where T_space is the ambient temperature (F) where the refrigerator is located and hr is the hour of the day.

HPXML Freezers

Each standalone freezer can be entered as a /HPXML/Building/BuildingDetails/Appliances/Freezer. If not entered, the simulation will not include a standalone freezer.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Location	string		See [839]	No	See [840]	Location
RatedAnnualkWh	double	kWh/yr	> 0	No	319.8 [841]	Annual consumption
extension/UsageMultiplier	double		>= 0	No	1.0	Multiplier on energy use
extension/WeekdayScheduleFractions	array		See [842]	No	See [843]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [844]	12 comma-separated monthly multipliers
extension/ConstantScheduleCoefficients	array			No		24 comma-separated constant coefficients
extension/TemperatureScheduleCoefficients	array			No		24 comma-separated temperature coefficients

[839]

Location choices are “conditioned space”, “basement - conditioned”, “basement - unconditioned”, “garage”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[840]

If Location not provided, defaults to “garage” if present, otherwise “basement - unconditioned” if present, otherwise “basement - conditioned” if present, otherwise “conditioned space”.

[841]

RatedAnnualkWh default based on the 2010 BAHSP.

[842]

Either schedule fraction inputs (WeekdayScheduleFractions/WeekendScheduleFractions/MonthlyScheduleMultipliers) or schedule coefficient inputs (ConstantScheduleCoefficients/TemperatureScheduleCoefficients) may be used, but not both.

[843]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs or schedule coefficients not used), then Default Schedules are used.

[844]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs or schedule coefficients not used), then Default Schedules are used.

Note

Freezer energy use is affected by its ambient temperature when ConstantScheduleCoefficients and TemperatureScheduleCoefficients are used, in which case hourly energy for freezers is determined following Equation 4.2-X2 of ANSI/RESNET/ICC 301-2022 Addendum C:

((RatedAnnualkWh / 8760) * (ConstantScheduleCoefficients[hr] + TemperatureScheduleCoefficients[hr] * T_space)

where T_space is the ambient temperature (F) where the freezer is located and hr is the hour of the day.

HPXML Dehumidifier

Each dehumidifier can be entered as a /HPXML/Building/BuildingDetails/Appliances/Dehumidifier. If not entered, the simulation will not include a dehumidifier.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Type	string		See [845]	Yes		Type of dehumidifier
Location	string		See [846]	Yes		Location of dehumidifier
Capacity	double	pints/day	> 0	Yes		Dehumidification capacity
IntegratedEnergyFactor or EnergyFactor	double	liters/kWh	> 0	Yes		Rated efficiency
DehumidistatSetpoint	double	frac	>= 0, <= 1 [847]	Yes		Relative humidity setpoint
FractionDehumidificationLoadServed	double	frac	>= 0, <= 1 [848]	Yes		Fraction of dehumidification load served

[845]

Type choices are “portable” or “whole-home”.

[846]

Location only choice is “conditioned space”.

[847]

If multiple dehumidifiers are entered, they must all have the same setpoint or an error will be generated.

[848]

The sum of all FractionDehumidificationLoadServed (across all Dehumidifiers) must be less than or equal to 1.

Note

Dehumidifiers are currently modeled as located within conditioned space; the model is not suited for a dehumidifier in, e.g., a wet basement or crawlspace where there is significant moisture from the ground. Therefore the dehumidifier Location is currently restricted to “conditioned space”. Like an HVAC system, the dehumidifier operates as needed to maintain the RH setpoint for the conditioned space.

HPXML Cooking Range/Oven

A single cooking range can be entered as a /HPXML/Building/BuildingDetails/Appliances/CookingRange. If not entered, the simulation will not include a cooking range/oven.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Location	string		See [849]	No	conditioned space	Location
FuelType	string		See [850]	Yes		Fuel type
IsInduction	boolean			No	false	Induction range?
extension/UsageMultiplier	double		>= 0	No	1.0	Multiplier on energy use
extension/WeekdayScheduleFractions	array			No	See [851]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [852]	12 comma-separated monthly multipliers

[849]

Location choices are “conditioned space”, “basement - conditioned”, “basement - unconditioned”, “garage”, “other housing unit”, “other heated space”, “other multifamily buffer space”, or “other non-freezing space”. See HPXML Locations for descriptions.

[850]

FuelType choices are “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “anthracite coal”, “electricity”, “wood”, or “wood pellets”.

[851]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[852]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

If a cooking range is specified, a single oven is also entered as a /HPXML/Building/BuildingDetails/Appliances/Oven.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
IsConvection	boolean			No	false	Convection oven?

Cooking range/oven energy use is calculated per the Energy Rating Rated Home in ANSI/RESNET/ICC 301-2019. If NumberofResidents provided, this will be adjusted using the equations from RECS in HPXML Building Occupancy.

HPXML Lighting & Ceiling Fans

Lighting and ceiling fans are entered in /HPXML/Building/BuildingDetails/Lighting.

HPXML Lighting

Lighting is described using multiple LightingGroup elements for each location (interior, exterior, or garage). If no LightingGroup elements are provided for a given location (e.g., exterior), the simulation will not include that lighting use.

Lighting can be specified in one of two ways:

• Lighting Type Fractions

• Annual Energy Consumption

With either lighting specification, additional information can be entered in /HPXML/Building/BuildingDetails/Lighting.

Element	Type	Units	Constraints	Required	Default	Notes
extension/InteriorUsageMultiplier	double		>= 0	No	1.0	Multiplier on interior lighting use
extension/GarageUsageMultiplier	double		>= 0	No	1.0	Multiplier on garage lighting use
extension/ExteriorUsageMultiplier	double		>= 0	No	1.0	Multiplier on exterior lighting use
extension/InteriorWeekdayScheduleFractions	array			No	See [853]	24 comma-separated interior weekday fractions
extension/InteriorWeekendScheduleFractions	array			No		24 comma-separated interior weekend fractions
extension/InteriorMonthlyScheduleMultipliers	array			No	See [854]	12 comma-separated interior monthly multipliers
extension/GarageWeekdayScheduleFractions	array			No	See [855]	24 comma-separated garage weekday fractions
extension/GarageWeekendScheduleFractions	array			No		24 comma-separated garage weekend fractions
extension/GarageMonthlyScheduleMultipliers	array			No	See [856]	12 comma-separated garage monthly multipliers
extension/ExteriorWeekdayScheduleFractions	array			No	See [857]	24 comma-separated exterior weekday fractions
extension/ExteriorWeekendScheduleFractions	array			No		24 comma-separated exterior weekend fractions
extension/ExteriorMonthlyScheduleMultipliers	array			No	See [858]	12 comma-separated exterior monthly multipliers

[853]

If InteriorWeekdayScheduleFractions or InteriorWeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[854]

If InteriorMonthlyScheduleMultipliers not provided (or Detailed Schedule Inputs not used), then Default Schedules are used.

[855]

If GarageWeekdayScheduleFractions or GarageWeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[856]

If GarageMonthlyScheduleMultipliers not provided (or Detailed Schedule Inputs not used), then Default Schedules are used.

[857]

If ExteriorWeekdayScheduleFractions or ExteriorWeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[858]

If ExteriorMonthlyScheduleMultipliers not provided (or Detailed Schedule Inputs not used), then Default Schedules are used.

Lighting Type Fractions

If specifying lighting type fractions, three /HPXML/Building/BuildingDetails/Lighting/LightingGroup elements (one for each possible LightingType) are entered for each lighting location:

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
LightingType	element		See [859]	Yes		Lighting type
Location	string		See [860]	Yes		Lighting location [861]
FractionofUnitsInLocation	double	frac	>= 0, <= 1 [862]	Yes		Fraction of light fixtures in the location with the specified lighting type

[859]

LightingType child element choices are LightEmittingDiode, CompactFluorescent, or FluorescentTube.

[860]

Location choices are “interior”, “garage”, or “exterior”.

[861]

Garage lighting is ignored if the building has no garage specified elsewhere.

[862]

The sum of FractionofUnitsInLocation for a given Location (e.g., interior) must be less than or equal to 1. If the fractions sum to less than 1, the remainder is assumed to be incandescent lighting.

Interior, exterior, and garage lighting energy use is calculated per the Energy Rating Rated Home in ANSI/RESNET/ICC 301-2019.

Annual Energy Consumption

If specifying annual energy consumption, a single /HPXML/Building/BuildingDetails/Lighting/LightingGroup element is entered for each lighting location:

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Location	string		See [863]	Yes		Lighting location [864]
Load[Units="kWh/year"]/Value	double	kWh/yr	>= 0	Yes		Lighting energy use

[863]

Location choices are “interior”, “garage”, or “exterior”.

[864]

Garage lighting is ignored if the building has no garage specified elsewhere.

Exterior Holiday Lighting

If exterior holiday lighting is specified, additional information is entered in /HPXML/Building/BuildingDetails/Lighting/extension/ExteriorHolidayLighting.

Element	Type	Units	Constraints	Required	Default	Notes
Load[Units="kWh/day"]/Value	double	kWh/day	>= 0	No	See [865]	Holiday lighting energy use per day
PeriodBeginMonth	integer		>= 1, <= 12	No	11 (November)	Holiday lighting start date
PeriodBeginDayOfMonth	integer		>= 1, <= 31	No	24	Holiday lighting start date
PeriodEndMonth	integer		>= 1, <= 12	No	1 (January)	Holiday lighting end date
PeriodEndDayOfMonth	integer		>= 1, <= 31	No	6	Holiday lighting end date
WeekdayScheduleFractions	array			No	See [866]	24 comma-separated holiday weekday fractions
WeekendScheduleFractions	array			No		24 comma-separated holiday weekend fractions

[865]

If Value not provided, defaults to 1.1 for single-family detached and 0.55 for others.

[866]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

HPXML Ceiling Fans

Each ceiling fan is entered as a /HPXML/Building/BuildingDetails/Lighting/CeilingFan. If not entered, the simulation will not include a ceiling fan.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Airflow[FanSpeed="medium"]/Efficiency and/or LabelEnergyUse	double	cfm/W or W	> 0	No	See [867]	Efficiency at medium speed or EnergyGuide label average energy use
Count	integer		> 0	No	See [868]	Number of similar ceiling fans
extension/WeekdayScheduleFractions	array			No	See [869]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [870]	12 comma-separated monthly multipliers

[867]

If Efficiency and LabelEnergyUse not provided, LabelEnergyUse defaults to 42.6 W based on ANSI/RESNET/ICC 301-2022 Addendum C. If both are provided, LabelEnergyUse will be used in the model.

[868]

If Count not provided, defaults to NumberofBedrooms + 1 based on ANSI/RESNET/ICC 301-2019.

[869]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[870]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), defaults based on monthly average outdoor temperatures per ANSI/RESNET/ICC 301-2019

Ceiling fan energy use is calculated per the Energy Rating Rated Home in ANSI/RESNET/ICC 301-2019.

Note

A reduced cooling setpoint can be specified for months when ceiling fans are operating. See HPXML HVAC Control for more information.

HPXML Pools & Permanent Spas

HPXML Pools

A single pool can be entered as a /HPXML/Building/BuildingDetails/Pools/Pool. If not entered, the simulation will not include a pool.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Type	string		See [871]	Yes		Pool type

[871]

Type choices are “in ground”, “on ground”, “above ground”, “other”, “unknown”, or “none”. If “none” is entered, the simulation will not include a pool. Any other value entered will indicate the presence of a pool; the specific value chosen does not affect the energy model.

Pool Pump

If a pool is specified, a single pool pump can be entered as a Pool/Pumps/Pump. If not entered, the simulation will not include a pool pump.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Type	string		See [872]	Yes		Pool pump type
Load[Units="kWh/year"]/Value	double	kWh/yr	>= 0	No	See [873]	Pool pump energy use
extension/UsageMultiplier	double		>= 0	No	1.0	Multiplier on pool pump energy use
extension/WeekdayScheduleFractions	array			No	See [874]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [875]	12 comma-separated monthly multipliers

[872]

Type choices are “single speed”, “multi speed”, “variable speed”, “variable flow”, “other”, “unknown”, or “none”. If “none” is entered, the simulation will not include a pool pump. Any other value entered will indicate the presence of a pool pump; the specific value chosen does not affect the energy model.

[873]

If Value not provided, defaults based on the 2010 BAHSP: 158.5 / 0.070 * (0.5 + 0.25 * NumberofBedrooms / 3 + 0.25 * ConditionedFloorArea / 1920). If NumberofResidents provided, this value will be adjusted using the equations from RECS in HPXML Building Occupancy.

[874]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[875]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

Pool Heater

If a pool is specified, a pool heater can be entered as a Pool/Heater. If not entered, the simulation will not include a pool heater.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Type	string		See [876]	Yes		Pool heater type
Load[Units="kWh/year" or Units="therm/year"]/Value	double	kWh/yr or therm/yr	>= 0	No	See [877]	Pool heater energy use
extension/UsageMultiplier	double		>= 0	No	1.0	Multiplier on pool heater energy use
extension/WeekdayScheduleFractions	array			No	See [878]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [879]	12 comma-separated monthly multipliers

[876]

Type choices are “none, “gas fired”, “electric resistance”, or “heat pump”. If “none” is entered, the simulation will not include a pool heater. Any other value entered will indicate the presence of a pool heater; the specific value chosen affects only the default kWh/year and therm/year values as described below.

[877]

If Value not provided, defaults as follows:

- gas fired [therm/year]: 3.0 / 0.014 * (0.5 + 0.25 * NumberofBedrooms / 3 + 0.25 * ConditionedFloorArea / 1920) (based on the 2010 BAHSP)

- electric resistance [kWh/year]: 8.3 / 0.004 * (0.5 + 0.25 * NumberofBedrooms / 3 + 0.25 * ConditionedFloorArea / 1920) (based on the 2010 BAHSP)

- heat pump [kWh/year]: (electric resistance [kWh/year]) / 5.0 (based on an average COP of 5 from Energy Saver)

If NumberofResidents provided, this value will be adjusted using the equations from RECS in HPXML Building Occupancy.

[878]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[879]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

HPXML Permanent Spas

A single permanent spa can be entered as a /HPXML/Building/BuildingDetails/Spas/PermanentSpa. If not entered, the simulation will not include a permanent spa.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Type	string		See [880]	Yes		Permanent spa type

[880]

Type choices are “in ground”, “on ground”, “above ground”, “other”, “unknown”, or “none”. If “none” is entered, the simulation will not include a permanent spa. Any other value entered will indicate the presence of a permanent spa; the specific value chosen does not affect the energy model.

Permanent Spa Pump

If a permanent spa is specified, a single permanent spa pump can be entered as a PermanentSpa/Pumps/Pump. If not entered, the simulation will not include a permanent spa pump.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Type	string		See [881]	Yes		Permanent spa pump type
Load[Units="kWh/year"]/Value	double	kWh/yr	>= 0	No	See [882]	Permanent spa pump energy use
extension/UsageMultiplier	double		>= 0	No	1.0	Multiplier on permanent spa pump energy use
extension/WeekdayScheduleFractions	array			No	See [883]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [884]	12 comma-separated monthly multipliers

[881]

Type choices are “single speed”, “multi speed”, “variable speed”, “variable flow”, “other”, “unknown”, or “none”. If “none” is entered, the simulation will not include a permanent spa pump. Any other value entered will indicate the presence of a permanent spa pump; the specific value chosen does not affect the energy model.

[882]

If Value not provided, defaults based on the 2010 BAHSP: 59.5 / 0.059 * (0.5 + 0.25 * NumberofBedrooms / 3 + 0.25 * ConditionedFloorArea / 1920). If NumberofResidents provided, this value will be adjusted using the equations from RECS in HPXML Building Occupancy.

[883]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[884]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

Permanent Spa Heater

If a permanent spa is specified, a permanent spa heater can be entered as a PermanentSpa/Heater. If not entered, the simulation will not include a permanent spa heater.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
Type	string		See [885]	Yes		Permanent spa heater type
Load[Units="kWh/year" or Units="therm/year"]/Value	double	kWh/yr or therm/yr	>= 0	No	See [886]	Permanent spa heater energy use
extension/UsageMultiplier	double		>= 0	No	1.0	Multiplier on permanent spa heater energy use
extension/WeekdayScheduleFractions	array			No	See [887]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [888]	12 comma-separated monthly multipliers

[885]

Type choices are “none, “gas fired”, “electric resistance”, or “heat pump”. If “none” is entered, the simulation will not include a permanent spa heater. Any other value entered will indicate the presence of a permanent spa heater; the specific value chosen affects only the default kWh/year and therm/year values as described below.

[886]

If Value not provided, defaults as follows:

- gas fired [therm/year]: 0.87 / 0.011 * (0.5 + 0.25 * NumberofBedrooms / 3 + 0.25 * ConditionedFloorArea / 1920) (based on the 2010 BAHSP)

- electric resistance [kWh/year]: 49.0 / 0.048 * (0.5 + 0.25 * NumberofBedrooms / 3 + 0.25 * ConditionedFloorArea / 1920) (based on the 2010 BAHSP)

- heat pump [kWh/year] = (electric resistance) / 5.0 (based on an average COP of 5 from Energy Saver)

If NumberofResidents provided, this value will be adjusted using the equations from RECS in HPXML Building Occupancy.

[887]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[888]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

HPXML Misc Loads

Miscellaneous loads are entered in /HPXML/Building/BuildingDetails/MiscLoads.

HPXML Plug Loads

Each type of plug load can be entered as a /HPXML/Building/BuildingDetails/MiscLoads/PlugLoad.

It is required to include miscellaneous plug loads (PlugLoadType=”other”), which represents all residual plug loads not explicitly captured elsewhere. It is common to include television plug loads (PlugLoadType=”TV other”), which represents all television energy use in the home. It is less common to include the other plug load types, as they are less frequently found in homes. If not entered, the simulation will not include that type of plug load.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
PlugLoadType	string		See [889]	Yes		Type of plug load
Load[Units="kWh/year"]/Value	double	kWh/yr	>= 0	No	See [890]	Annual electricity consumption
extension/FracSensible	double		>= 0, <= 1	No	See [891]	Fraction that is sensible heat gain to conditioned space [892]
extension/FracLatent	double		>= 0, <= 1	See [893]	See [894]	Fraction that is latent heat gain to conditioned space
extension/UsageMultiplier	double		>= 0	No	1.0	Multiplier on electricity use
extension/WeekdayScheduleFractions	array			No	See [895]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [896]	12 comma-separated monthly multipliers

[889]

PlugLoadType choices are “other”, “TV other”, “well pump”, or “electric vehicle charging”.

[890]

If Value not provided, defaults as follows when NumberofResidents is not provided:

- other: 0.91 * ConditionedFloorArea (based on ANSI/RESNET/ICC 301-2019)

- TV other: 413.0 + 69.0 * NumberofBedrooms (based on ANSI/RESNET/ICC 301-2019)

- well pump: 50.8 / 0.127 * (0.5 + 0.25 * NumberofBedrooms / 3 + 0.25 * ConditionedFloorArea / 1920) (based on the 2010 BAHSP)

- electric vehicle charging: 2368.4 (calculated using AnnualMiles * kWhPerMile * FractionChargedAtHome / (ChargerEfficiency * BatteryEfficiency) where AnnualMiles=10900, kWhPerMile=0.22, FractionChargedAtHome=0.8, ChargerEfficiency=0.9, and BatteryEfficiency=0.9). If this plug load type is specified, it will take precedence over an EV specified in HPXML Vehicles.

If NumberofResidents is provided, the following defaults are used instead:

- other (single-family detached): 786.9 + 241.8 * NumberofResidents + 0.33 * ConditionedFloorArea (based on RECS 2020)

- other (single-family attached): 654.9 + 206.5 * NumberofResidents + 0.21 * ConditionedFloorArea (based on RECS 2020)

- other (apartment unit): 706.6 + 149.3 * NumberofResidents + 0.10 * ConditionedFloorArea (based on RECS 2020)

- other (manufactured home): 1795.1 (based on RECS 2020)

- TV other (single-family detached): 334.0 + 92.2 * NumberofResidents + 0.06 * ConditionedFloorArea (based on RECS 2020)

- TV other (single-family attached): 283.9 + 80.1 * NumberofResidents + 0.07 * ConditionedFloorArea (based on RECS 2020)

- TV other (apartment unit): 190.3 + 81.0 * NumberofResidents + 0.11 * ConditionedFloorArea (based on RECS 2020)

- TV other (manufactured home): 99.9 + 129.6 * NumberofResidents + 0.21 * ConditionedFloorArea (based on RECS 2020)

- well pump: Same as above, but this value will be adjusted using the equations from RECS in HPXML Building Occupancy.

- electric vehicle charging: Same as above

[891]

If FracSensible not provided, defaults as:

- other: 0.855

- TV other: 1.0

- well pump: 0.0

- electric vehicle charging: 0.0

[892]

The remaining fraction (i.e., 1.0 - FracSensible - FracLatent) must be > 0 and is assumed to be heat gain outside conditioned space and thus lost.

[893]

FracLatent only required if FracSensible is provided.

[894]

If FracLatent not provided, defaults as:

- other: 0.045

- TV other: 0.0

- well pump: 0.0

- electric vehicle charging: 0.0

[895]

If WeekdayScheduleFractions or WeekdendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[896]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

HPXML Fuel Loads

Each fuel load can be entered as a /HPXML/Building/BuildingDetails/MiscLoads/FuelLoad.

It is less common to include fuel load types, as they are less frequently found in homes. If not entered, the simulation will not include that type of fuel load.

Element	Type	Units	Constraints	Required	Default	Notes
SystemIdentifier	id			Yes		Unique identifier
FuelLoadType	string		See [897]	Yes		Type of fuel load
Load[Units="therm/year"]/Value	double	therm/yr	>= 0	No	See [898]	Annual fuel consumption
FuelType	string		See [899]	Yes		Fuel type
extension/FracSensible	double		>= 0, <= 1	No	See [900]	Fraction that is sensible heat gain to conditioned space [901]
extension/FracLatent	double		>= 0, <= 1	See [902]	See [903]	Fraction that is latent heat gain to conditioned space
extension/UsageMultiplier	double		>= 0	No	1.0	Multiplier on fuel use
extension/WeekdayScheduleFractions	array			No	See [904]	24 comma-separated weekday fractions
extension/WeekendScheduleFractions	array			No		24 comma-separated weekend fractions
extension/MonthlyScheduleMultipliers	array			No	See [905]	12 comma-separated monthly multipliers

[897]

FuelLoadType choices are “grill”, “fireplace”, or “lighting”.

[898]

If Value not provided, calculated as based on the 2010 BAHSP:

- grill: 0.87 / 0.029 * (0.5 + 0.25 * NumberofBedrooms / 3 + 0.25 * ConditionedFloorArea / 1920)

- fireplace: 1.95 / 0.032 * (0.5 + 0.25 * NumberofBedrooms / 3 + 0.25 * ConditionedFloorArea / 1920)

- lighting: 0.22 / 0.012 * (0.5 + 0.25 * NumberofBedrooms / 3 + 0.25 * ConditionedFloorArea / 1920)

If NumberofResidents provided, this value will be adjusted using the equations from RECS in HPXML Building Occupancy.

[899]

FuelType choices are “natural gas”, “fuel oil”, “fuel oil 1”, “fuel oil 2”, “fuel oil 4”, “fuel oil 5/6”, “diesel”, “propane”, “kerosene”, “coal”, “coke”, “bituminous coal”, “anthracite coal”, “wood”, or “wood pellets”.

[900]

If FracSensible not provided, defaults to 0.5 for fireplace and 0.0 for all other types.

[901]

The remaining fraction (i.e., 1.0 - FracSensible - FracLatent) must be > 0 and is assumed to be heat gain outside conditioned space and thus lost.

[902]

FracLatent only required if FracSensible is provided.

[903]

If FracLatent not provided, defaults to 0.1 for fireplace and 0.0 for all other types.

[904]

If WeekdayScheduleFractions or WeekendScheduleFractions not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

[905]

If MonthlyScheduleMultipliers not provided (and Detailed Schedule Inputs not used), then Default Schedules are used.

HPXML Locations

The various locations used in an HPXML file are defined as follows:

Value	Description	Temperature	Building Type
outside	Ambient environment	Weather data	Any
ground		EnergyPlus foundation model calculation	Any
conditioned space	Above-grade conditioned space maintained at setpoint	EnergyPlus thermal zone calculation	Any
attic - vented		EnergyPlus thermal zone calculation	Any
attic - unvented		EnergyPlus thermal zone calculation	Any
basement - conditioned	Below-grade conditioned space maintained at setpoint	EnergyPlus thermal zone calculation	Any
basement - unconditioned		EnergyPlus thermal zone calculation	Any
crawlspace - vented		EnergyPlus thermal zone calculation	Any
crawlspace - unvented		EnergyPlus thermal zone calculation	Any
crawlspace - conditioned	Below-grade conditioned space maintained at setpoint	EnergyPlus thermal zone calculation	Any
garage	Unconditioned garage (not shared parking garage) [906]	EnergyPlus thermal zone calculation	Any
manufactured home underbelly	Underneath the belly, ambient environment	Weather data	Manufactured only
manufactured home belly	Within the belly	Same as conditioned space	Manufactured only
other housing unit	E.g., conditioned adjacent unit or conditioned corridor	Same as conditioned space	SFA/MF only
other heated space	E.g., shared laundry/equipment space	Avg of conditioned space/outside; min of heating setpoint	SFA/MF only
other multifamily buffer space	E.g., enclosed unconditioned stairwell	Avg of conditioned space/outside; min of 50F	SFA/MF only
other non-freezing space	E.g., shared parking garage ceiling	Floats with outside; minimum of 40F	SFA/MF only
other exterior	Water heater outside	Weather data	Any
exterior wall	Ducts in exterior wall	Avg of conditioned space/outside	Any
under slab	Ducts under slab (ground)	EnergyPlus foundation model calculation	Any
roof deck	Ducts on roof deck (outside)	Weather data	Any

[906]

OpenStudio-HPXML does not model “conditioned” or “heated” garages. Many conditioned garages are not conditioned 24/7, rather they are only conditioned for short periods when occupants are in them and turn on the space conditioning equipment, so it is best to assume an unconditioned garage. However, if a garage was converted into livable space, then “conditioned space” should be used instead.

Note

All conditioned space in a dwelling unit (i.e., “conditioned space”, “basement - conditioned”, and “crawlspace - conditioned”) is modeled as a single thermal zone, in which a single air temperature/humidity is calculated for each timestep.

Validating & Debugging Errors

When running HPXML files, errors may occur because:

1. An HPXML file provided is invalid (either relative to the HPXML schema or the EnergyPlus Use Case).

2. An unexpected EnergyPlus simulation error occurred.

If an error occurs, first look in the run.log for details. If there are no errors in that log file, then the error may be in the EnergyPlus simulation – see eplusout.err.

Contact us if you can’t figure out the cause of an error.

Sample Files

Dozens of sample HPXML files are included in the workflow/sample_files directory. The sample files help to illustrate how different building components are described in HPXML.

Each sample file generally makes one isolated change relative to the base HPXML (base.xml) building. For example, the base-dhw-dwhr.xml file adds a DrainWaterHeatRecovery element to the building.

You may find it useful to search through the files for certain HPXML elements or compare (diff) a sample file to the base.xml file.