Use of these dryer has increased in last few year. As suggested in name it cool the air up to 30C at certain pressure. So, its give 30C pressure dew point and (-30 to -20)0C atm dew point depending upon the pressure of air. There is no air loss in this type of air dryer.
Recommended for capacities from 2 NM3 / hr to 500 NM3 /hr. Minimum Air pressure should be 4 Kg /cm2g. These air dryer are not suggested to rural remote place, where availability of technician is difficult.