Coeficiente de Performance (COP)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
COP = Q_C/W
About this calculator
This calculator determines the Coefficient of Performance (COP) for refrigeration systems or heat pumps. COP is the ratio of useful thermal energy transferred (Q_C) to electrical work consumed (W). For refrigerators, Q_C is the heat removed from the cold space; for heat pumps, it is the heat supplied to the warm space. COP is dimensionless, and a higher value indicates greater efficiency.
The calculation is straightforward: COP = Q_C / W. The values of Q_C and W must be in the same energy unit (e.g., joules, kWh). Enter the data in the respective fields and click 'Calculate'. The result displays the COP, which typically ranges from 2 to 6 for household refrigerators and 3 to 5 for heat pumps, depending on operating conditions.
Use this tool to compare the efficiency of different equipment, size systems, or verify the performance of an existing appliance. For instance, when buying an air conditioner, a higher COP indicates lower energy consumption for the same cooling capacity. It is also useful in engineering projects to optimize HVAC systems.
Precautions: ensure Q_C and W are in the same unit. COP does not account for system losses like friction or motor inefficiencies. For a complete analysis, consider the Seasonal COP (SCOP) that reflects climate variations. Remember: COP is an instantaneous ratio; under real conditions, the value may fluctuate with ambient temperature and thermal load.
Frequently asked questions
What does a high COP mean?
A high COP indicates greater efficiency: more thermal energy is transferred per unit of electrical work consumed. For example, COP=5 means for every 1 kWh of electricity, 5 kWh of heat is moved.
What is the difference between COP and EER?
COP is used for both cooling and heating, while EER (Energy Efficiency Ratio) is specific to cooling and uses different units (BTU/h per watt). Both measure efficiency, but COP is dimensionless.
Can I use COP to compare different types of systems?
Yes, as long as operating conditions are similar. Systems with higher COP are more efficient, but factors like initial cost and maintenance should also be considered.
Does COP vary with outdoor temperature?
Yes, especially for heat pumps. The larger the temperature difference between sources, the lower the COP. Therefore, SCOP (Seasonal COP) is used for annual averages.
How do I convert COP to percentage efficiency?
COP is not a percentage but a ratio. For refrigeration systems, the theoretical maximum efficiency is given by the Carnot cycle, and the actual COP is compared to that limit.