An Energy Recovery Ventilator (ERV) is the system used for energy recovery by exchanging the energy contained in air exhausted from the building and using it to treat (pre-conditioned) the incoming outdoor ventilation air in residential and commercial HVAC systems. (So it is basically a spinning hamster wheel working to make your home more comfortable.) During the warmer months, the system dehumidifies and pre-cools while humidifying and pre-heating in the cooler months. The benefits of using energy recovery is the ability to meet the ASHRAE ventilation and energy standards, while improving indoor air quality, and reducing total HVAC equipment capacity. It does not make your home more energy-efficient, this is used with a focus on comfort and indoor air-quality.