Heat recovery is an energy efficiency initiative that can result in dramatic energy use reductions and bring down costs by as much as a third.

In buildings where it is necessary that the air that heats, cools or ventilates is only used once (hospitals, research facilities, clean rooms etc), much of the HVAC energy can be recovered before it exits the building by installing heat-recovery coils into the exhaust air handlers. This heat can be subsequently used to precondition the outside air entering the building.

Waste heat recovery on boiler stacks can be used to preheat boiler makeup water, thereby improving overall energy efficiency substantially. Heat recovery from stacks in heat treating furnaces is frequently used to preheat combustion air, thereby achieving savings of well over 50%.

Other examples of the use of heat exchangers include:

• Condensing steam from a boiler to produce hot water for service hot water or other processes;
• Isolating two systems which operate at different pressures while extracting heat from the higher temperature system;
• Moving heat or cool in various refrigerator cycles that may include changing of state from liquids to gases in the heat exchanger; and
• Moving heat into and out of thermal storage containers.