The principle of air source heat pump is the use of inverse Carnot principle, the use of very little electric energy, absorb a large amount of low-temperature heat energy in the air (low-grade energy), through the compression of the compressor into high-temperature heat energy, is a high-efficiency and energy-saving heat pump technology. When the air source heat pump is in operation, with the refrigerant as the medium, the evaporator absorbs heat from the air of the external environment to transfer heat to the refrigerant, and the pressure of the refrigeration steam rises after being compressed by the compressor and becomes steam of high temperature and high pressure. the high temperature steam is bonded to the wall of the condenser and condensed into a liquid, and the heat released is transferred to the corresponding medium (water or air). Then flow through the expansion valve to reduce the pressure and return to the liquid state of low temperature and low pressure, thus completing a cycle.