COP

Metrics and Efficiency Ratings - Heat Pumps pillar

Also known as: Coefficient of Performance

Coefficient of Performance. The instantaneous ratio of useful heat moved to electricity consumed by a heat pump. A COP of 3.0 means 3 units of heat per 1 unit of electricity.

COP is the instantaneous efficiency ratio of a heat pump or refrigeration cycle. A heat pump with COP 3.0 delivers 3 kWh of heat for every 1 kWh of electricity input, which is impossible for resistance heating and is the entire economic case for heat pumps. COP varies with outdoor temperature: a cold-climate heat pump might run COP 4.0 at +7C and COP 1.8 at -25C. HSPF2 is the seasonally-averaged equivalent. Heat pump water heaters typically run COP 2.5 to 4.0 depending on basement air temperature.

See the full Ontario HVAC and home energy glossary or browse the Heat Pumps pillar.