The combined air conditioning unit is one of the most important equipment for air treatment. It does not have a cold or heat source. It uses cold, hot water or steam as a medium to complete the filtration, purification, heating, cooling and humidification of the air. , dehumidification, silencer, fresh air treatment and other functions of box combined unit. The fresh air enters the air conditioning unit and mixes with the return air from the room in the mixing section. The mixed air passes through the primary filter section to remove dust and debris, and then passes through the intermediate filter section for secondary filtration to remove smaller dust and debris. Then, the air is cooled or heated through the surface cooling section or heating section to reach the required temperature point, and then humidified through the humidifying section to the humidity required by the system, that is, it reaches the designated air supply status point, and finally through the fan Section sends the processed air into the room.