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 compresses the high-pressure liquid refrigerant into a gas state through an expansion valve, absorbing a large amount of heat from the air in the evaporator. The gaseous refrigerant is then compressed by the compressor into a high-temperature, high-pressure liquid and enters the condenser to release heat, thereby heating the water... This continuous circulation process can heat water to between 50°C and 65°C.