The SMART ERV uses patented poly-wheel technology to pump out stale air and pump in fresh air while capturing up to 80% of the energy within the exhaust. It constantly supplies fresh air to provide a healthy indoor environment by reducing odors and/or indoor pollutants. It also humidifies or dehumidifies the home as required. This product promotes indoor air quality, as well as energy efficiency. Contact: (800) 443-6341 (United States) or (888) SELKIRK 735-5475 (Canada).