Heat Pump COP Calculator

Enter source and sink temperatures to calculate the ideal Carnot COP and estimated real-world COP for a heat pump in heating or cooling mode.

Input Parameters

Heat pump: extracts heat from a cold source and delivers it to a warm space.

°C
°C
Carnot COP (Ideal Maximum)

Theoretical upper limit; no real device can exceed this.

Estimated Real-World COP

Estimated at ~50% of Carnot COP, typical for vapor-compression systems.

Details

Temperature Lift
Cold Side (Kelvin)
Hot Side (Kelvin)
vs. Resistance Heater
Real-World COP vs. Carnot

Summary

Enter source and sink temperatures to calculate the ideal Carnot COP and estimated real-world COP for a heat pump in heating or cooling mode.

How it works

  1. Select operating mode: heating (heat pump) or cooling (refrigerator/AC).
  2. Enter the cold-side temperature (source for heating, sink for cooling).
  3. Enter the hot-side temperature (sink for heating, source for cooling).
  4. The calculator uses absolute temperatures (Kelvin) for Carnot formulas.
  5. Carnot COP_heating = T_hot / (T_hot − T_cold); Carnot COP_cooling = T_cold / (T_hot − T_cold).
  6. Real-world COP is estimated at 40–60% of Carnot COP, typical for modern equipment.

Use cases

  • Estimate heat pump efficiency before purchasing or installing a unit.
  • Compare heating vs. cooling performance at different outdoor temperatures.
  • Understand how temperature lift affects heat pump efficiency.
  • Calculate energy savings versus a resistance heater (COP > 1 = savings).
  • Academic and engineering coursework on thermodynamic cycles.
  • HVAC system sizing and energy auditing.

Frequently Asked Questions

Last updated: 2026-06-10 · Reviewed by Nham Vu