Air source heat pump water heater (heater) unit is different from electric water heater (heater) unit. Electric water heater (heater) unit uses electric heating tube to directly convert electrical energy into heat to heat cold water. The highest conversion efficiency of electricity to heat is about 95℅. However, the electric energy consumed by the air heat pump water heater (heater) unit drives the heat pump to work, and only plays a role in promoting the circulation of the heat medium. Because a large amount of heat in the air enters the system, the energy obtained by the hot water is much greater than that consumed by the heat pump. For electric energy, the ratio of these two energies can reach more than 3-4 times, that is, the conversion rate of electricity to heat is as high as 400℅. That is to say: the main energy for heating water in the air source heat pump water heater (heater) unit system is from the surrounding air, and enough electricity can be obtained by using 1/3 or 1/4 of the electricity consumed by the electric water heater (heater) unit. For hot water, the operating cost is obviously much lower than that of electric water heaters or electric boilers.