One type of charge-air cooler (CAC) is an air-to-air cooler (ATAC). These are also known as intercoolers
as distinct from pre-coolers, which can be water-cooled. And ATACs are distinct from liquid-to-air
coolers, which include radiators and various oil coolers.
Huge ATACs are commonly employed in power generators and diesel locomotives. In these applications,
the mechanical energy from the diesel engines is converted to electrical energy by an electric generator.