Heat Pump Manuals & Owner Guides

SEER2, EER2 and HSPF2 explained

SEER2

Seasonal cooling efficiency measured under the 2023 DOE test procedure (M1), which uses higher external static pressure than the old SEER test. Higher is better.

EER2

Cooling efficiency at a single hot condition (95 °F outdoors). Important in hot climates where peak demand matters.

HSPF2

Seasonal heating efficiency. ENERGY STAR heat pumps must meet minimum HSPF2 values; cold-climate models also report capacity and COP at 5 °F.

COP at 5 °F

Units of heat delivered per unit of electricity at 5 °F outdoors. A COP of 2.0 means twice as efficient as electric resistance heat.

Why the AHRI matched system matters

Heat pump efficiency is certified for specific combinations of outdoor unit, indoor coil or air handler, and sometimes furnace. The AHRI reference number identifies that exact combination. Utilities and rebate programs typically require it, so ask your contractor for the AHRI certificate with your quote.

Cold-climate heat pumps

ENERGY STAR cold-climate heat pumps must maintain a COP of at least 1.75 at 5 °F and retain a high share of their rated heating capacity in frigid weather. In northern climates, compare capacity at 5 °F against your home's design heat loss to see how much backup heat you will need.

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