The COP (Coefficient of Performance) of a heat pump is an index that describes the efficiency of converting the energy input into heat energy. It is equal to the ratio of the heating power the heat pump can provide to the power input. For example, if COP is 4, it means that the heat pump needs to consume 1 kilowatt of electrical energy to produce 4 kilowatts of heat energy. Thus, three-quarters of the energy for heating comes from the outside environment, making the heat pump an efficient means of heating. A high COP indicates a higher efficiency of the heat pump and therefore lower running costs for the user. However, it is worth remembering that the actual COP can vary depending on the operating conditions, such as outdoor temperature and room temperature.