A heat recovery ventilator (HRV)
uses virtually noise-free fans that draw in fresh, cool outdoor air, while removing stale, heated indoor air. An energy recovery ventilator (ERV)
performs the same function, but utilizes a rotary energy recovery wheel. In both cases, the units transfer the temperature and moisture properties from one air stream to the other, without allowing the two airflow streams to mix. Both units offer easy access for change of filters and necessary maintenance, making them not only energy efficient but also easy to use.