The refrigeration system consists of 4 basic parts, namely, compressor, condenser, throttling components, and evaporator. The four pieces are connected in a certain order by the copper pipe to form a closed system, and the system is filled with a certain amount of refrigerant. The general air-conditioning refrigerant is Freon, R22 is usually used in the past, and some air-conditioning Freon has adopted a new type of environmentally friendly refrigerant R407. The above is a vapor compression refrigeration system. Taking refrigeration as an example, the compressor sucks in low-temperature and low-pressure Freon gas from the evaporator and compresses it into high-temperature and high-pressure Freon gas, and then flows through the thermal expansion valve (capillary tube) to throttle into a low-temperature and low-pressure Freon vapor-liquid two-phase object. Then the low-temperature and low-pressure Freon liquid absorbs the heat from the indoor air in the evaporator and becomes low-low-temperature and low-low-low-pressure Freon gas. After the indoor air passes through the evaporator, it releases heat and the air temperature drops. In this way, compression-condensation-throttling-evaporation cycles repeatedly, and the refrigerant continuously takes away the heat of the indoor air, thereby reducing the temperature of the room. During heating, the flow direction of the refrigerant is changed by switching the four-way valve, so that the outdoor heat exchanger becomes an evaporator, which absorbs the heat of the outdoor air, while the indoor evaporation becomes a condenser, which dissipates the heat indoors. To achieve the purpose of heating.