Van Air AC Series Air Cooled Aftercoolers utilize free and readily available atmospheric air as the cooling medium. Standard models are rated to 3500 SCFM. Hot moist air from the compressor is cooled rapidly to a safe, usable temperature by the Van Air triple-cool process. The AC Series Air-Cooled Aftercoolers utilize atmospheric air as the cooling medium. As the compressed air is cooled a substantial amount of moisture is condensed and collected into the separator installed on the aftercooler outlet. Install indoors or out.