Called Fresh Air In-Forcer, the system consists of a fan and exterior hood that can be installed through a 4-inch round exterior wall opening. According to the manufacturer, it is an effective, affordable way to supply fresh outside air to dilute trapped pollutants and replace air vented by exhaust fans and fuel-burning equipment in residential structures. Operating control options include manual operation by plugging into a 115-vac switched outlet, plug-in timer operation for a desired schedule, or dehumidistat control operation. Standard 4-inch flex or metal duct may be used for ducting. The quiet, high-efficiency 90-cfm fan consumes 18W.
Tjernlund Products Inc.