Refrigerated air dryer

Refrigerated air dryers remove moisture from compressed air by chilling it to roughly +38 deg F (+3 deg C), at which point excess water vapor condenses and is drained off. The treated air is then reheated by the incoming wet air in an air-to-air heat exchanger, conserving energy and avoiding cold downstream piping.

What it is

A refrigerated dryer is essentially a small chiller. Wet compressed air enters an air-to-air pre-cooler, then a refrigerant-to-air evaporator, then a moisture separator with automatic drain. Cool, dry air returns through the pre-cooler picking up heat on the way out. Cycling and non-cycling control architectures trade capital cost against part-load efficiency.

Why it matters

Refrigerated dryers handle the vast majority of compressed-air drying duty in industry. They cannot reach the very low dew points required for instrument and critical applications, but for general plant air, pneumatic tools, and indoor distribution, a +38 deg F pressure dew point eliminates the practical risk of liquid water and is far cheaper to run than a desiccant dryer.

How it is used in our catalog

Refrigerated dryers are the largest category in our dryer catalog. Filter by SCFM at rated inlet pressure and check the published pressure dew point for the specific model. Pair with class pages like rotary screw compressors for sized package quotes.

Common questions

Why +38 deg F and not lower?

Cooling below 33 deg F freezes the condensate inside the evaporator. +38 deg F is the practical minimum that gives margin against freeze-up.

Do I need a refrigerated dryer for outdoor distribution?

If any piping drops below the pressure dew point, you do. For outdoor or unheated indoor runs in cold climates, a desiccant dryer or trace-heated piping may be necessary.