Energy recovery ventilation

Energy recovery ventilation (ERV) is the energy recovery process of exchanging the energy contained in normally exhausted building or space air and using it to treat (precondition) the incoming outdoor ventilation air in residential and commercial HVAC systems. During the warmer seasons, the system pre-cools and dehumidifies while humidifying and pre-heating in the cooler seasons. The benefit of using energy recovery is the ability to meet the ASHRAE ventilation & energy standards, while improving indoor air quality and reducing total HVAC equipment capacity.

This technology has not only demonstrated an effective means of reducing energy cost and heating and cooling loads, but has allowed for the scaling down of equipment. Additionally, this system will allow for the indoor environment to maintain a relative humidity of 40% to 50%. This range can be maintained under essentially all conditions. The only energy penalty is the power needed for the blower to overcome the pressure drop in the system.

Nearly half of global energy is used in buildings, and half of heating/cooling cost is caused by ventilation when it is done by the "open window" method according to the regulations [define method and include citation]. Secondly, energy generation and grid is made to meet the peak demand of power. To use proper ventilation; recovery is a cost-efficient, sustainable and quick way to reduce global energy consumption and give better indoor air quality (IAQ) and protect buildings (Sick Building Syndrome, SBS) and environment.

An energy recovery ventilator (also abbreviated ERV) is a type of air-to-air heat exchanger that not only transfers sensible heat but also latent heat. Because both temperature and moisture are transferred, ERVs can be considered total enthalpic devices. On the other hand, a heat recovery ventilator (HRV) can only transfer sensible heat. HRVs can be considered sensible only devices because they only exchange sensible heat. In other words, whereas all ERVs are HRVs, not all HRVs are ERVs, but many people use the terms HRV, AAHX (air-to-air heat exchanger), and ERV interchangeably.

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