In the treatment of compressed air, air dryers using refrigeration operate continuously. They cool the air to a dew point in the 35 to 39 F range. The condensated moisture is expelled continuously through a trap on a timer.

The initial cost of a refrigerated dryer is less than a regenerating desiccant dryer, but the operating cost is higher. Also, the dew point only goes to + 35 F. The installation is simple, requiring only the air and drain hook up plus the electric power connection.

Refrigerated dryers can operate at higher air inlet temperatures and higher pressures than desiccators. For critical applications, refrigeration is used before a desiccant dryer.