Cooling¶
Table of Contents
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.
| 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.
| 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, EER), 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.
| Cooling Type | Efficiency Units |
|---|---|
| split_dx | SEER |
| packaged_dx | EER |
| heat_pump | SEER |
| mini_split | 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 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.