4 Inch Draft Blocker Backdraft Damper Duct Draft Stopper, One-Way Airflow Ducting Insert Backflow Preventer Inline Fan Vent Deflector for 4 Inch Duct Dryer Vent Hose(2Pcs)

Features:What Is a Backdraft Damper?A backdraft damper, also known as a gravitydamper, is a piece of equipment that allows air to flow through in onedirection while preventing air from entering the opposite side, also known as abackdraft. Backdraft dampers assist in the exhaust or intake of heating,ventilation, and air conditioning (HVAC) systems.Why Do I Need a Backdraft Damper?A backdraft damper is beneficial if you arelooking to control and enhance the air quality of your home or office.Installing a damper keeps temperature-controlled or purified air within yourspace while simultaneously keeping outside air from coming in. A backdraftdamper is useful in controlling temperature but can also be used to improve theventilation of a space.Ideal for all tumble dryer vent pipes / hoses,bathroom extractors and vents, air conditioning and heating units, kitchenvents and fans, all home wall and ceiling vents, heat transfer and ventilationsystems, gas and electric dryers, cooker hood extractors, as well as a widevariety of industrial uses.

• 【Function】This airflow regulating backdraft shutter fits over the TD lip and is designed to improve ventilation by preventing air from re-circulating when the fans are not in use
• 【Material】4 Inch backdraft damper and the flap leaves is made of a galvanized steel, the axis are made of aluminum, while the spring are made of carbon steel.
• 【Installation】The backflow flap is installed by inserting it into the ventilation pipe until it stops. The position of the spring should be horizontal for horizontal installations so that it can open and close optimally. The Backdraft shutter is installed so that the damper blades open only in the outflowing air direction.
• 【Wide Application】Back draught valves can be inserted into havc ducting which are flexible or non-flexible. Designed for use with range hoods, bathroom fans, kitchen and other home HVAC applications
• 【Quiet Work】The valve wings open under the pressure created by the airflow; when the air flows in the opposite direction, it is automatically closed under the action of the spring, so as to cut off the flow. Note: Back draught valves can be inserted into ventilation ducts which are flexible or non flexible. Cannot be used with plastic ducts as the sizes are different.