Calculate the Coefficient of Performance (COP) for your heat pump. Determine heating efficiency by comparing heat output to electrical input.
COP (Coefficient of Performance) is the fundamental measure of heat pump efficiency. It expresses how many units of heat energy the pump delivers for each unit of electrical energy consumed. A COP of 3.0 means the heat pump delivers 3 BTU of heat for every 1 BTU equivalent of electricity used.
COP varies with outdoor temperature — higher COP in mild weather, lower COP in extreme cold. A typical air-source heat pump achieves COP 3–4 at 47°F but may drop to COP 1.5–2.0 at 5°F. Ground-source (geothermal) heat pumps maintain COP 3–5 year-round because ground temperature is constant.
This calculator computes COP from heat output and electrical input. Understanding your heat pump's COP at different temperatures helps you optimize setpoints and decide when backup heating is more economical.
Understanding this metric in precise terms allows energy managers to evaluate investment options, forecast savings, and build compelling business cases for efficiency upgrades and retrofits.
COP tells you the real-time efficiency of your heat pump. Knowing when COP drops below the break-even point versus your backup heating source helps you optimize energy costs throughout the heating season. Having accurate metrics readily available streamlines utility bill analysis, budget forecasting, and investment planning for energy efficiency projects and renewable energy installations.
COP = Heat Output (BTU/hr) / (Watts Input × 3.412 BTU/W) Equivalent Efficiency = COP × 100%
Result: COP = 3.01
A heat pump delivering 36,000 BTU/hr of heat while consuming 3,500 watts: COP = 36,000 / (3,500 × 3.412) = 36,000 / 11,942 = 3.01. This means the heat pump is 301% efficient — it delivers 3 times more heat energy than the electricity it consumes.
Heat pumps don't create heat — they move it from outside to inside using a refrigerant cycle. The electricity powers this transfer, not the heating itself. This is why a heat pump can deliver 3+ BTU of heat for every BTU of electricity used. It's not magic; it's thermodynamics.
If you have a dual-fuel system (heat pump + gas furnace), COP tells you when to switch fuels. Calculate the break-even COP: Break-even COP = (Electricity Price per BTU) / (Gas Price per BTU). When actual COP drops below this value, gas is cheaper.
Ground-source heat pumps maintain COP 3–5 regardless of outdoor temperature because ground temperature is constant (50–60°F). Air-source COP varies from 4+ in mild weather to under 2 in extreme cold. For consistent high efficiency, ground-source is superior but costs 2–3× more to install.
COP 3.0–4.0 is good for air-source heat pumps at moderate temperatures (40–50°F). COP above 4.0 is excellent. Ground-source heat pumps routinely achieve COP 3.5–5.0. Any COP above 1.0 outperforms electric resistance heating.
Air-source heat pump COP drops as outdoor temperature decreases. Typical values: COP 4.0 at 50°F, COP 3.0 at 35°F, COP 2.0 at 15°F, COP 1.5 at 0°F. Cold-climate heat pumps maintain higher COP at low temperatures.
COP measures instantaneous efficiency at a specific temperature. HSPF measures seasonal average efficiency across all heating temperatures. HSPF = average COP × 3.412. COP is useful for comparing operating costs at specific conditions.
When electricity costs more than 2.5–3× gas per BTU, gas heating is cheaper. At typical rates ($0.13/kWh and $1.20/therm), a heat pump is cheaper than gas as long as COP stays above about 2.0. This varies by local energy prices.
Lower the supply temperature (use radiant floor or fan coils instead of standard ducts), keep the outdoor unit clear of ice and debris, maintain clean filters, and ensure proper refrigerant charge. A heat pump with proper maintenance operates at peak COP.
In cooling mode, COP = cooling output / electrical input. Air conditioners typically have cooling COP of 3–5 (equivalent to EER 10–17). Cooling COP is related to EER: COP = EER / 3.412.