A recuperator is a device used to reclaim heat energy from a heating, ventilation and air-conditioning (HVAC) system or industrial process. This device helps to improve energy efficiency, which can reduce costs associated with heating or manufacturing. Depending on the application, a recuperator may also be known as a heat exchanger or heat recovery unit.
These units are commonly found within the HVAC systems of a building. The recuperator is installed within the duct work just before the exhaust vents or grills. A pair of parallel plates within the unit separate hot air from cool air, directing the air to two separate locations. Cool air is simply expelled from the building through traditional exhaust systems, while the hot air is directed back into the supply ducts for reuse within the heating system.
Different types of recuperator designs can impact the heat recovery capabilities of these systems. Vertical units are the least efficient, and consist of vertical plates within a large outer casing. Horizontal units, which are more compact and utilize horizontal plates, tend to be more efficient. The most efficient units feature an internal cellular structure, which recovers up to 99 percent of heat energy.
An HVAC recuperator may not be used year round in areas with hot summers and cold winters. Instead, users rely on a series of dampers to bypass the recuperator when it is not needed. For example, during the summer, the damper will be shut to prevent air from reaching the recuperator. Instead, all exhaust air is simply expelled to the outdoors and there is no need or desire to keep heat energy circulating within the building.
A similar technology is used to recover heat energy in manufacturing or industrial facilities. Many of these facilities rely on a gas turbine engine, which utilizes a mixture of hot air and fuel to produce a combustion process. Generally, the air must be heated prior to combustion using an additional heat source. In buildings with a recuperator, the hot air exhaust produced by combustion is simply recirculated back into the engine to mix with fuel and power the next round of combustion. This eliminates the need for a second heat source and also helps to reduce fuel costs associated with heating.
Recuperators offer many advantages to homeowners, business owners, and society as a whole. By improving energy efficiency, they help to cut fuel costs and even improve comfort in a home or commercial building. This improvement in energy efficiency also reduces dependence on fossil fuels like coal and oil. By limiting dependence on these fuels, heat recovery devices help to reduce pollution and greenhouse gas emissions and preserve limited resources.