GEM Equipments Limited offers Refrigerated Air Dryers having R22 Refrigerant. GEM Equipments Limited offers a varied range of solutions to plant engineering & utility requirements. Refrigerated Air Dryers Having R22 Refrigerant works on the basic principle involving removal of moisture by cooling air to certain present temperature. There is no process known for producing cold, there is only heat removal. Heat is always attracted by the cold body. This is the basis for the operation of a cooling unit. As long as the temperature of the cold body is lower than the hot source, there will be heat transfer.