1. Air-cooled aftercoolers cool the hot air using ambient air. Hot compressed air enters the air-cooled aftercooler and travels through a spiral finned tube coil, while ambient air is sucked in through the cooler by a fan. The cooler ambient air removes heat from the compressed air.

2. Water-cooled aftercoolers use water to cool the hot compressed air. Compressed air enters the water-cooled aftercooler and travels through a tube bundle while water is circulated around the tubes. The water absorbs the heat from the compressed air and Water condensed due to cooling effect should be removed from the system and that is where moisture separators come into picture.