Heating Seasonal Performance Factor (HSPF)

Heating Seasonal Performance Factor (HSPF) is an efficiency rating for heat pumps in heating mode. It’s the total heating output (measured in BTUs) over a typical heating season divided by the total electrical energy input in watt-hours consumed in that season. A higher HSPF value means the heat pump provides more heat per unit of energy, translating to lower heating costs. HSPF 9 or above is common in modern heat pumps.