How to Use Coefficient of Performance Calculator
The Coefficient of Performance Calculator tells you how efficiently a heat pump, chiller, or air conditioner converts input work into useful heating or cooling. Use it to compare spec-sheet numbers, validate field measurements, or estimate operating cost.
- Pick the mode — Choose cooling (COP = Qc/W) for chillers and ACs, or heating (COP = Qh/W) for heat pumps.
- Choose input type — Enter either steady-state power (W, kW, BTU/h) or total energy (J, kJ, kWh, BTU).
- Read the COP — The Coefficient of Performance Calculator outputs a clean dimensionless number plus a short interpretation.
Formula & Theory - Coefficient of Performance Calculator
The Coefficient of Performance Calculator is based on the standard definition:
COP = Useful Heat or Cooling Output / Input Work or Electrical Energy
COP_cooling = Qc / W
COP_heating = Qh / WFor systems where output and input are measured over the same time interval, you can use power or energy interchangeably:
COP = Q̇ / Ẇ (instantaneous power)
COP = E_out / E_in (energy over a time interval)| Symbol | Meaning |
|---|---|
| Qc | Cooling capacity (or cooling energy delivered) |
| Qh | Heating capacity (or heating energy delivered) |
| W | Input work (or electrical energy consumed) |
Assumptions and Limits
- The calculator assumes steady-state operation; transient startup losses are ignored.
- It does not include defrost cycles, auxiliary resistance heat, or fan/pump power unless you include them in W.
- For accurate seasonal estimates, use HSPF (heating) or SEER (cooling) instead, which integrate over weather.
Use Cases for Coefficient of Performance Calculator
- HVAC selection — Compare candidate heat pumps and chillers on a level dimensionless basis.
- Field testing — Compute measured COP from datalogger output and input readings.
- Engineering homework — Verify thermodynamics-class problems quickly.
- Energy auditing — Spot-check whether an installed system meets manufacturer claims.
The Coefficient of Performance Calculator delivers a fast, transparent metric for any heating or cooling system.