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

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