Rooftop air conditioning unit is a kind of large and medium-sized integral air conditioning equipment with its own cooling source and air cooling. Its refrigeration, heating, humidification, air supply, air purification and electrical control are assembled in a horizontal box. According to the specific requirements of the environment where the unit is used, the unit can take explosion-proof, anti-corrosion and other treatment measures. The roof type air conditioning unit has its own cold source. It is an air conditioning unit composed of compressed air-cooled condenser and refrigerant expansion type direct evaporator. It does not need cooling water and cooling water system. It saves cooling tower, cooling water pump, cooling water pump and corresponding pipelines, and some electric control devices. It is widely used in large and medium-sized plants and workshops where it is inconvenient to install water system and where water resources are scarce Adjustment of humidity, cleanliness and other parameters.