Heat Pump COP Calculator
Calculate the coefficient of performance (COP) of a heat pump or refrigeration system.
Compare to Carnot COP and estimate energy savings.
The Coefficient of Performance (COP) measures how efficiently a heat pump or refrigerator works:
Heat pump (heating mode): COP_heating = Q_hot / W = Heat delivered / Electrical work input
Refrigerator/air conditioner (cooling mode): COP_cooling = Q_cold / W = Heat removed from cold space / Work input
The relationship between heating and cooling COP: COP_heating = COP_cooling + 1
Maximum possible COP (Carnot): COP_heating_max = T_hot / (T_hot − T_cold) COP_cooling_max = T_cold / (T_hot − T_cold)
What does COP mean in practice?
A COP of 3.5 for heating means: for every 1 kW of electricity consumed, the heat pump delivers 3.5 kW of heat to your home.
Compare to:
- Electric resistance heater: COP = 1.0 (converts electricity to heat directly)
- Heat pump (air source, mild climate): COP = 2.5–5.0
- Heat pump (ground source): COP = 3.0–6.0
This is why heat pumps are far more efficient than electric heaters — they “move” heat rather than generating it.
Energy efficiency rating:
- SEER (Seasonal Energy Efficiency Ratio): cooling rating for AC units (SEER = 12 ≈ COP = 3.5)
- HSPF (Heating Seasonal Performance Factor): heating rating
- EER = BTU/(Wh) = COP × 3.412 for cooling