http://en.wikipedia.org/wiki/Thermal_efficiency#Heat_pumps_and_refrigerators http://en.wikipedia.org/wiki/Thermal_efficiency#Heat_pumps_a... The expression "co

http://en.wikipedia.org/wiki/Thermal_efficiency#Heat_pumps_and_refrigerators http://en.wikipedia.org/wiki/Thermal_efficiency#Heat_pumps_a... The expression "coefficient of performance" is used instead of efficiency for heat pump.