Heating

Heating system type

HPXML provides two difference HVAC system elements that can provide heating: HeatingSystem that only provides heating and HeatPump which can provide heating and cooling.

Heat Pump

The HeatPump element in HPXML can represent either an air-source heat pump or ground source heat pump in HEScore. Which is specified in HEScore is determined by the HeatPumpType element in HPXML according to the following mapping.

Heat Pump Type mapping

HPXML Heat Pump Type	HEScore Heating Type
water-to-air	gchp
air-to-air	heat_pump
mini-split	mini_split
ground-to-air	gchp
water-to-water	not translated
air-to-water	not translated
ground-to-water	not translated
water-loop-to-air	not translated
variable refrigerant flow	not translated
packaged terminal heat pump	not translated
room air conditioner with reverse cycle	not translated

The primary heating fuel is assumed to be electric.

Warning

If an HPXML heat pump type maps to not translated the translation will fail.

Note

Prior to HEScore v2016 mini-split heat pumps were translated as ducted air-source heat pumps with ducts in conditioned space. With the addition of mini split heat pumps in HEScore v2016, they are now categorized appropriately.

If a heat pump has a FractionCoolLoadServed set to zero, the heat pump is assumed to provide only space heating. If the heat pump is connected to the same distribution system as a separate cooling system and serves the same portion of the house, the house will translate but fail in Home Energy Score because that configuration is not supported.

Heating System

The HeatingSystem element in HPXML is used to describe any system that provides heating that is not a heat pump. The HeatingSystemType subelement is used to determine what kind of heating system to specify for HEScore. This is done according to the following mapping.

Heating System Type mapping

HPXML Heating System Type	HEScore Heating Type
Furnace	central_furnace
WallFurnace	wall_furnace
FloorFurnace	wall_furnace
Boiler	boiler
ElectricResistance	baseboard
Stove	wood_stove
Fireplace	not translated
PortableHeater (HPXML V2 and HPXML V3)	not translated
SpaceHeater	not translated
SolarThermal	not translated
DistrictSteam	not translated
Other	not translated

Warning

If an HPXML heating system type maps to not translated the translation will fail.

A primary heating fuel is selected from the HeatingSystemFuel subelement of the primary heating system. The fuel types are mapped as follows.

Primary Heating System Fuel mapping

HPXML	HEScore
electricity	electric
renewable electricity	electric
natural gas	natural_gas
renewable natural gas	natural_gas
fuel oil	fuel_oil
fuel oil 1	fuel_oil
fuel oil 2	fuel_oil
fuel oil 4	fuel_oil
fuel oil 5/6	fuel_oil
propane	lpg
wood	cord_wood
wood pellets	pellet_wood

Warning

HPXML supports other fuel types that could not be mapped into existing HEScore fuel types (i.e. coal, wood). Encountering an unsupported fuel type will result in a translation error.

Heating Efficiency

Heating efficiency can be described in HEScore by either the rated efficiency (AFUE, HSPF, HSPF2, COP), or if that is unavailable, the year installed/manufactured from which HEScore estimates the efficiency based on shipment weighted efficiencies by year. The translator follows this methodology and looks for the rated efficiency first and if it cannot be found sends the year installed.

Wood stoves and electric furnaces and baseboard heating do not use the efficiency input in HEScore. Therefore, for these heating types an efficiency is not determined.

Rated Efficiency

HEScore expects efficiency to be described in different units depending on the heating system type.

HEScore heating type efficiency units

Heating Type	Efficiency Units
heat_pump	HSPF2, HSPF
mini_split	HSPF2, HSPF
central_furnace	AFUE
wall_furnace	AFUE
boiler	AFUE
gchp	COP

The translator searches the HeatingSystem/AnnualHeatingEfficiency or HeatPump/AnnualHeatEfficiency (HPXML v2) or HeatPump/AnnualHeatingEfficiency (HPXML v3) elements of the primary heating system.

Both AnnualHeatingEfficiency(or AnnualHeatEfficiency)/Units and AnnualHeatingEfficiency(or AnnualHeatEfficiency)/Value are searched and expected to match the above table, with precedence to first/newer units.

Shipment Weighted Efficiency

When an appropriate rated efficiency cannot be found, HEScore can accept the model year or year the equipment was installed and estimate the efficiency based on that. The year is retrieved from the ModelYear element, and if that is not present the YearInstalled element.