Air Source Heat Pumps, also known as "Air Source Heat Pump Water Heaters," operate on a principle very similar to air conditioners. They use a small amount of electricity to power the compressor, which then compresses the liquid working substance. After passing through an expansion valve, the substance evaporates into a gas state in the evaporator, absorbing a large amount of heat from the air. The gaseous substance is compressed into a high-temperature, high-pressure liquid by the compressor and then enters the condenser to release heat and heat the water. This continuous cycle of heating can raise the water temperature to between 50°C and 65°C.