Air conditioning is air conditioning. Refers to the equipment that manually adjusts and controls the temperature, humidity, flow rate and other parameters of ambient air in buildings or structures. Generally, it includes cold and heat source equipment, cold and heat medium transmission and distribution system, terminal device and other auxiliary equipment. It mainly includes refrigeration host, water pump, fan and pipeline system. The terminal equipment is responsible for carefully handling the air state by using the cold heat from transmission and distribution, so that the air parameters of the target environment can meet the requirements.