Water has the ability to evaporate in the air. When there is no other heat source, the heat and humidity exchange process between water and air is that the air transfers sensible heat to water, causing the air temperature to drop. Because of the evaporation of water, the moisture content of the air will not only increase, but also the water vapor entering the air will bring back some latent heat of vaporization. When the two kinds of heat are equal, the water temperature reaches the wet bulb temperature of the air. As long as the air is not saturated, the cooling effect can be obtained by spraying air directly (or through the packing layer) with circulating water. When conditions permit, the cooled air can be used as air supply to lower the room temperature. This method of air treatment is called evaporative cooling air conditioning.

Evaporative cooling air conditioning technology is an environmentally friendly, efficient and economical cooling method.