The Filter-Vent combines air filtration with fresh air ventilation. Indoor air recirculates and passes through high-efficiency filters. The filter has a dust spot efficiency of 95 percent, compared to less than 10 percent for the typical furnace filter.

Because a small amount of fresh air is introduced, the building operates under a slightly positive pressure. That keeps dust and unfiltered air out of the house. Positive pressure also prevents backdrafting of combustion devices, such as fireplaces and gas water heaters. The manufacturer claims that moisture problems will not develop in structural cavities because indoor humidity levels are kept low. However, if you build in a moist coastal climate, that may not hold true.

The 110 watt motor uses much less energy to circulate air than the larger motors in forced air systems. The fan delivers 200 cfm at 0.4 in. w.g.

The filter unit can be connected to its own delivery ducts or attached to the heating and cooling system. Exhaust fans for the kitchen and bathrooms must be provided separately.

Contact: Therma-stor Products