Heat Pump COP Calculator

About the Heat Pump COP Calculator

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.

When This Page Helps

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.

How to Use the Inputs

1. Enter the heat output in BTU/hr.
2. Enter the electrical power input in watts.
3. The calculator computes COP and equivalent efficiency.
4. Compare COP at different outdoor temperatures.
5. Determine the break-even point vs electric resistance or gas.

Example Calculation

Tips & Best Practices

• COP above 1.0 means the heat pump is more efficient than electric resistance heating.
• COP of 2.5–3.5 is typical for air-source heat pumps at moderate temperatures.
• Ground-source heat pumps achieve COP 3–5 year-round.
• When COP drops below ~2.0–2.5, gas heating may be cheaper depending on fuel prices.
• Variable-speed heat pumps maintain higher COP at partial loads.
• COP improves with lower lift (smaller difference between source and delivery temperature).

How Heat Pumps Achieve COP > 1

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.

COP and Operating Cost Decisions

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 vs Air-Source COP

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.

Frequently Asked Questions

• What is a good heat pump COP?

  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.

• How does COP change with temperature?

  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.

• What's the difference between COP and HSPF?

  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 is a heat pump less efficient than gas?

  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.

• How can I improve my heat pump's COP?

  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.

• What is COP for cooling mode?

  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.