Cooling

Cooling system type

HPXML provides two difference HVAC system elements that can provide cooling: CoolingSystem that only provides cooling 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 Cooling Type
water-to-air	gchp
water-to-water	gchp
air-to-air	heat_pump
mini-split	mini_split
ground-to-air	gchp

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 FractionHeatlLoadServed set to zero, the heat pump is assumed to provide only space cooling. If the heat pump is connected to the same distribution system as a separate heating 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.

Cooling System

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

Cooling System Type mapping

HPXML Cooling System Type	HEScore Cooling Type
central air conditioner (HPXML V3)	split_dx
central air conditioning (HPXML V2)	split_dx
room air conditioner	packaged_dx
mini-split	mini_split
evaporative cooler	dec
other	not translated

Warning

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

Note

Prior to v2016, HEScore did not have an evaporative cooler type and these were translated as high efficiency split_dx systems. Now that evaporative cooling has been added in HEScore v2016, they are categorized accordingly.

Note

Starting from HPXML version 3.0, the enumeration “central air conditioning” is renamed as “central air conditioner”. They’re equivalent in translation.

Cooling Efficiency

Cooling efficiency can be described in HEScore by either the rated efficiency (SEER, SEER2, EER, CEER), 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. Evaporative coolers do not require an efficiency input in HEScore, and it is therefore omitted.

Rated Efficiency

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

HEScore cooling type efficiency units

Cooling Type	Efficiency Units
split_dx	SEER2, SEER
packaged_dx	CEER, EER
heat_pump	SEER2, SEER
mini_split	SEER2, SEER
gchp	EER

The translator searches the CoolingSystem/AnnualCoolingEfficiency or HeatPump/AnnualCoolEfficiency (HPXML v2) or HeatPump/AnnualCoolingEfficiency (HPXML v3) elements of the primary cooling system.

Both AnnualCoolingEfficiency(or AnnualCoolEfficiency)/Units and AnnualCoolingEfficiency(or AnnualCoolEfficiency)/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 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.