# 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
water-to-water gchp
air-to-air heat_pump
mini-split mini_split
ground-to-air gchp

The primary heating fuel is assumed to be electric.

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

Note

HPXML supports other values for the HeatingSystemType element not in the list above, but HEScore does not. Other heating system types will result in a translation error.

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, 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 HSPF
mini_split 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 and uses the first one that has the correct units.

### Shipment Weighted Efficiency¶

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