Fantech's smallest and most compact side duct connection HRV, the SH 704 unit brings a continuous supply of fresh air into a home while exhausting an equal amount of contaminated air. During winter, fresh incoming air is tempered by the heat that is transferred from the outgoing air so you save on energy costs, while during summer, the incoming air is pre-cooled if the house is equipped with an air cooling system. The SH 704 is equipped with automatic defrost mechanisms so you can use your HRV all year long. Unit is designed to operate continuously on a single speed.
The automatic defrost cycle consists of a fan shutdown. When the supply air stream temperature goes below 23degrees Fahrenheit, the supply motor shuts down while the exhaust motor continues to ventilate. Ambient air is passed through the unit for a period of 3 or 5 minutes. The supply motor will then re-start and run at the preset speed.