An aftercooler is a heat exchanger for cooling air from compressors, designed to reduce the temperature and liquefy condensate vapors. Both air cooled and water cooled units are common.Aftercoolers lower the temperature and remove water from the air.

Aftercoolers control water vapor in a system by condensing the vapor into liquid. Liquid water can cause significant damage to equipment that uses compressed air. An aftercooler is necessary to guarantee the proper functioning of devices that are part of process manufacturing systems.