Search query: 3 inch backdraft damper

Product: Back Draft Blocker, Backdraft Damper Dryer Vent Hose, Inline Extractor Fan Vent Back Draught Shutter (4'' Inch)
Brand: Repa Market
Relevance: Substitute
Prevent drafts with our Plastic Dryer Vent Draft Blocker. When your clothes dryer is in use, the exhaust opens the built-in damper. Gravity keeps it closed when you’re not drying laundry. Plastic Is Very Durable. Damper unit comes fully assembled, and installs to the clothes dryer duct and vent pipe. Great for kitchen hood fan. PLASTIC RECTANGULAR AND ROUND SYSTEM Plastic air ducts are designed for use in small living spaces and of ce premises, where the ventilation system is most often locted under a suspended ceiling. Plastic rectangular or round system allows easy installation of small air lines with different turning angles for the horizontal and vertical planes, due to the available convenient auxiliary connections and adapters.
Perfectly suited for ducting your Bathroom or Kitchen extractor fan, Hydroponics, In-Line Extract Fans, or Cooker Hood, Prevent cold air from entering your home through the dryer vent with our inline dryer vent draft blocker
Comes with balanced damper fully assembled, stops unpleasant odours, noises, or draughts flowing back through your duct
This backdraught shutter can be used as a part of a long duct run for a variety of purposes including whole house ventilation, passive stack vent, air conditioning, positive pressure, Tumble Dryer Venting, HVAC, and Heat Recovery Systems
White Plastic Extractor Fan Backdraught Shutter - Male Spigot - External diameter is ~ 124mm
Compatible with diameter 4 Inch. Easy to DIY!

Product: Butterfly Backdraft Damper (7 Inch) (BD 7)
Brand: HVAC Express
Relevance: Substitute
Backdraft damper with lightweight blades and foam closure to eliminate noise and increase efficiency. Proven design to protect against backdraft in your appliance venting Easy to install, heavy duty 26 gauge galvanized metal Foamed shutter system for quiet closure Vertical or horizontal mounting, with one end crimped Dampers are available in sizes 3" up to 24" ducting. Specifications Sheet - Butterfly Backdraft Damper
Backdraft damper with lightweight blades and foam closure shutter for quiet closure
Proven design to protect against backdraft in your appliance venting
Vertical or horizontal mounting, with one end crimped
Heavy-duty 26 gauge galvanized metal
Made in the USA