compressed air is directly cooled by a refrigerant in a heat exchanger, an indirect cooling-type air dryer enables the cooling and dehumidification of compressed air through an intermediate heating medium.

GSA’s compressed air dryer is highly reliable and efficient in use

Auxiliary Equipment for Compressed Air Treatment

Indirect Cooling-type Air Dryer

Unlike a direct cooling system in which compressed air is directly cooled by a refrigerant in a heat exchanger, an indirect cooling-type air dryer enables the cooling and dehumidification of compressed air through an intermediate heating medium. For the intermediate heating medium, cooling water such as brine is commonly used.

A conventional direct cooling system consists of two different heat exchangers such as air-to-air heat exchanger and an air-to-REF heat exchanger. In contrast, an indirect cooling air dryer is comprised of three heat exchangers: air-to-air, heating medium-to-REF and heating medium-to-air heat exchangers. A coolant fluid used as a heating medium is usually high in heat capacity and specific heat. As a result, it ensures
more stable dew points in certain circumstances such as rapid increase in load compared with a direct cooling method.

Direct Cooling Indirect Cooling
Heat Exchanger Air to Air Air to Air
Air to Ref Cooling medium to Ref.
- Cooling medium to Ref.
System Configuration Relatively simple Complicated
Application Good for small-medium size Good for large size
Dew Point Relatively stable More stable than direct cooling
Indirect cooling air dryer
Certification mark