A constant temperature and humidity air conditioning unit typically features an evaporator (finned tube type) of the refrigeration system installed in the air-handling channel, cooling the air through the direct evaporation of the refrigerant. When using a constant temperature and humidity unit to process air, not only can it lower or raise the temperature and humidity, but it can also automatically control the temperature and humidity of the adjusted room within a specific range. Therefore, it is often used for industrial production air conditioning.