Abstract: A self-closing vent intended for use in attics, crawl spaces, joist cavities, exterior walls, interior walls, or other structural element which allows for the free flow of air from outside a building to interior spaces during normal use. The vent includes a damper blade pivotally connected to, and disposed within, the vent housing, which is held in an open position by a temperature sensitive fusible link. Two, and preferably three, permanent magnets provide the force for driving the damper blade into a closed and locked position. A first magnet disposed in a side of the vent housing and a second magnet disposed on the damper blade are disposed with opposing (repelling) polarities when the damper blade is held in the open position. A third magnet disposed proximate the back of the vent housing is oriented so as to attract the magnet disposed on the damper blade.

Abstract: A magnetically controlled flow system having a pivotable flap with a permanent magnet at distal ends. Two coils with magnetizable cores are mounted inside the duct and positioned so as to cooperate with the permanent magnet when the flap is in either a closed or an open position. By energizing the coils, the permanent magnet is attracted to the magnetizable cores in either one of the coils, thereby actuating the flap between the closed and open positions.

Abstract: A flue seal (10) utilized in conjunction with a flue (12) within a fireplace (14). The flue seal (10) has a magnetic sheet (18) positionable within the flue (12). The magnetic sheet (18) has a sheet opening (18a) therethrough. A fastener (20) is securely connected through the sheet opening (18a). A pull chain (22) is securely connected to the fastener (20) extending downwardly therefrom.

Abstract: An anti-draft shutter assembly for an axial flow fan fitted to a duct. The assembly includes at least one counterbalanced flap supported downstream of airflow from the fan when in operation, and at least one of the flaps being pivotally supported outside the perimeter of the duct. The flap is biased by a counterbalance weight toward a duct closing position to close the duct when the fan is not operating. In the preferred embodiment, at least one flap is held in the closed position by a magnetic catch on the flap.

Abstract: A latch for use with a valve on the end of an exhaust vent typically associated with a clothes dryer or the like. The latch includes a flat, plastic bonded magnet having a layer of pressure sensitive adhesive (PSA) for bonding the magnet to one of either the hinged valve plate or stationary face plate of the valve while a strike plate formed of a conformable, magnetically susceptible material is bonded by a PSA layer to an opposing section of the other of the valve plate or face plate. The latch is kept closed by magnetic forces in the absence of blower expelled air, regardless of variations in pressure on the valve plate, such as may result from gusts of wind.

Abstract: A ventilation system for ventilating the inside of a compartment such as the compartment of an automobile or the room of a building. The ventilation system prevents the contaminated outside air from flowing back into the inside of the compartment from an inside air outlet by magnetically attracting a mouth frame, which is composed of the inside air outlet and a peripheral edge, and a one-way valve for opening the inside air outlet only at the time of releasing the inside air of the compartment to the outside.