How it works? The water vapor partial pressure in the compressed air and the characteristics determined by the compressed air temperature are used for cooling, dehydration and drying. In the case of keeping the compressed air pressure basically constant, reducing the temperature of the compressed air can reduce the water vapor content in the compressed air, and the excess water vapor will condense into a liquid. The cold dryer uses this principle to dry compressed air with refrigeration technology, so the cold dryer has a refrigeration system.