What defines the efficiency of a heat pump system?

The efficiency of a heat pump system is primarily defined by its coefficient of performance (COP). The COP is a ratio that measures the amount of heating or cooling provided by the heat pump in relation to the amount of energy consumed. A higher COP indicates a more efficient heat pump, meaning it puts out more heating or cooling energy than the energy it consumes. This efficiency metric is crucial for understanding how effectively the system operates, especially in terms of energy savings and overall performance.

While the ability to cool effectively is important, it does not directly quantify efficiency and can vary depending on environmental conditions and system design. The size of the unit can also contribute to its overall performance, but it does not directly define efficiency without reference to output versus input energy. The color of the external casing is purely aesthetic and has no bearing on the system's operational efficiency. Understanding COP helps homeowners and inspectors evaluate and compare the performance of different heat pump systems.