Aluminum  heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another. The classic example of a heat exchanger is found in an internal combustion engine in which a circulating fluid known as engine coolant flows through radiator coils and air flows past the coils, which cools the coolant and heats the incoming air.  They are widely used in space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, natural gas processing, and sewage treatment.  The media may be separated by a solid wall, so that they never mix, or they may be in direct contact.