Coefficient of Performance (Cooling)

The coefficient of performance for cooling tells you how much heat a refrigeration or air-conditioning system removes from a cold space for each unit of work it consumes. It works because a refrigerator does not create cold; it uses input work to move thermal energy from inside the cooled space to the warmer surroundings. Since the useful output in cooling is the heat removed from the space, a larger COP means the system delivers more cooling for the same electrical power.

Use this when evaluating refrigerators, freezers, air conditioners, chillers, or heat pumps operating in cooling mode. It is especially useful for comparing energy efficiency across different systems or estimating how much cooling you get from a known power input.

• Using the heat rejected to the room instead of the heat removed from the cooled space
• Putting temperature values into the formula instead of heat flow and work
• Forgetting that COP is a ratio and has no units