Most exchangers consist of a stack of ribbed plates.
Heated air flows on one side of each plate, while cooler air flows on the other side of the plate. The warmer air heats the plate and transfers heat to the air on the cooler side. Heat exchangers themselves have no moving parts and can be located in any relatively clean air streams. Heat exchangers should be considered in new construction or renovation of bathroom, shower, kitchen, medical facilities and laboratories, dining and other building areas normally exhausted. Heat exchangers work both directions, effectively reducing both heating and cooling loads.