Heat Pump System Type Definitions

Modified on Mon, 11 Aug at 10:30 AM

If the air conditioner or heat pump’s efficiency is rated in SEER2 or HSPF2, the choice of Heat Pump System Type will update the conversion factor to SEER or HSPF for the energy calculations, as specified in ANSI-301. The conversion factors are specified in this article.

To model a ductless system, please select as the Distribution Type in your heat pump ‘Forced Air Ductless’ or ‘Radiant’, based on configuration of the distribution system. Then select ‘Unspecified’ as the Heat Pump System type. Selecting a ductless option for your distribution will override the conversion factors given by the ‘Unspecified’ Heat Pump System Type, setting the SEER2/SEER conversion factor to 1, and the HSPF2/HSPF conversion factor to 0.9.

The table below defines the terminology of the different types of ducted heat pump systems, with the definitions from sections 3.1.51 through 3.1.56 of the AHRI Standards 210/240-2023 (2020).

Heat Pump System Type Definitions

Unspecified	If the system type of your heat pump is unknown, it will be defaulted to Ducted Split System as per ANSI / RESNET / ICC 301.
Ducted Split System	“Any central air-conditioner or heat pump that has at least two separate assemblies that are connected with refrigerant piping when installed. At least one of these assemblies is an Indoor Unit and at least one of these assemblies is an Outdoor Unit. Split Systems may be either Blower Coil Systems or Coil-only Systems.” Can be Single Split systems (One indoor and one outdoor unit), Multi-head Mini-Split systems (2+ indoor units controlled by the same thermostat, and one outdoor unit), or Multi-Split systems (2+ indoor units independently controlled and one outdoor unit).
Ducted Package System	“Any central air-conditioner or heat pump that has all major assemblies enclosed in one cabinet.”
Small Duct High Velocity	“A Split System for which all Indoor Units are Blower Coil Indoor Units that produce at least 1.2 in H2O of ESP when operated at the full-load air volume rate Specified by the manufacturer of at least 220 scfm per rated ton of cooling.”
Duct Space-Constrained	A central air-conditioner or heat pump with rated cooling capacities no greater than 30k Btu/h, with dimensions substantially smaller than other units usually installed in Single Family homes, but with a similar heating/cooling capacity, which can’t be increased in size without significant cost increases.