Heat recovery

Heat recovery ventilation (HRV), also known as mechanical ventilation heat recovery (MVHR) is a ventilation system that recovers energy by operating between two air sources at different temperatures. It is used to reduce the heating and cooling demands of buildings.

Energy recovery ventilation (ERV) is the energy recovery process in residential and commercial HVAC systems that exchanges the energy contained in normally exhausted air of a building or conditioned space, using it to treat (precondition) the incoming outdoor ventilation air. The specific equipment involved may be called an Energy Recovery Ventilator, also commonly referred to simply as an ERV.

The following table summarizes various heat and energy recovery options.

Heat recovery types comparison. (Source: IBPSA-USA BEMP Training Workshop)

Type	Heat Transfer	Humidity Transfer	Typical Application	Rule-of-Thumb Effectiveness
Run-Around Coil	Sensible Only	None	Labs, hospitals, critical environments	45 – 67%
Heat Pipe	Sensible Only	None	Offices, dry climates	50 – 70%
Enthalpy Wheels	Sensible & Latent	Moderate	Large office buildings, all climates	65 – 85%
Plate HX	Sensible	None	Cleanrooms	50 – 70%