空调分为单冷空调和冷暖两用空调，工作原理是一样的，空调一般使用的制冷剂是氟利昂。 氟利昂的特性是：由气态变为液态时，释放大量的热量。而由液态转变为气态时，会吸收大量的热量。空调就是据此原理而设计的。
Air conditioning is divided into single cooling air conditioning and dual-purpose air conditioning. The working principle is the same. Freon is the refrigerant commonly used in air conditioning. Freon is characterized by the release of a large amount of heat when it changes from a gaseous state to a liquid state. When it changes from liquid to gas, it will absorb a lot of heat. Air conditioning is designed according to this principle.
压缩机将气态的制冷剂压缩为高温高压的气态制冷剂，然后送到冷凝器（室外机）散热后成为常温高压的液态制冷剂，所以室外机吹出来的是热风。
The compressor compresses the gaseous refrigerant into the gaseous refrigerant of high temperature and pressure, and then sends it to the condenser (outdoor unit) for heat dissipation to become the liquid refrigerant of normal temperature and pressure, so the outdoor unit blows out the hot air.
然后到毛细管，进入蒸发器（室内机），由于制冷剂从毛细管到达蒸发器后空间突然增大，压力减小，液态的制冷剂就会汽化，变成气态低温的制冷剂，从而吸收大量的热量，蒸发器就会变冷，室内机的风扇将室内的空气从蒸发器中吹过，所以室内机吹出来的就是冷风；空气中的水蒸汽遇到冷的蒸发器后就会凝结成水滴，顺着水管流出去，这就是空调会出水的原因。
Then it goes to the capillary and enters the evaporator (indoor unit). Since the space of the refrigerant suddenly increases after it reaches the evaporator from the capillary and the pressure decreases, the liquid refrigerant will vaporize and become the refrigerant of gas state and low temperature, so as to absorb a lot of heat, and the evaporator will become cold. The fan of the indoor unit blows the indoor air out of the evaporator, so what the indoor unit blows out is Cold air: when the water vapor in the air meets the cold evaporator, it will condense into water drops and flow out along the water pipe, which is the reason why the air conditioner will come out of the water.
制热的时候有一个叫四通阀的部件，使制冷剂在冷凝器与蒸发器的流动方向与制冷时相反，所以制热的时候室外吹的是冷风，室内机吹的是热风。
When heating, there is a component called a four-way valve, which makes the flow direction of refrigerant in the condenser and evaporator opposite to that of refrigeration. Therefore, when heating, the air is cold outside and the air is hot inside.