An energy recovery ventilator (ERV) is a type of air-to-air heat exchanger that transfers heat between exhaust and fresh airstreams. The heat exchanger is designed for the two airstreams to pass one another and exchange energy in the form or heat - all without the two airstreams contaminating one another. In the cooling season, the hot and humid ventilation air is cooled slightly by the exhaust air, resulting in less energy spent lowering the ventilation air to an appropriate level for distribution to the building. In the winter, the opposite happens as the ventilation air is warmed by the exhaust air, resulting in less energy spent in warming the ventilation air to the appropriate level.
Because these devices are used to save energy, EC motor technology is the most sensible choice for driving supply and exhaust fans. EC technology provides high-efficiency at 100% capacity and allows for variable speed operation which provide additional energy savings and accurate delivery of airflow.