6" Draft Blocker Back Draft Damper Duct Draft Stopper One-Way Airflow Duct Backflow Prevention Inline Fan Vent Deflector

works great for my microwave vent

I have allergies and apparently if I leave my portable Danby AC connected to the Window I wake up wheezing with Asthma or rather a type of bronchitis that fills my lungs with mucus from the allergies. Coughing and wheezing throughout the night. I had no idea that a backdraft damper existed or at least I could imagine that it existed but I had to search for "AC Duct air Blocker" to find that what I was looking for was a backdraft blocker. Measured twice the size of my Duct and it turns out that there are only three sizes 4", 6" and 8". My duct was 6.5". When my Draft Blocker arrived and I fitted it into the duct it was loosely fitted so I added a foam seal around the draft blocker and that made the backdraft blocker a tighter fit. Wasn't sure how far to push it into the duct but on the first try I decided to just have it near the entrance of the duct and that should be good enough. Checked that it was closed when my AC is not on and checked that I had Air flow when I turned on my AC by checking outside whether there was hot air blowing out of the exhaust. Yup works wonderfully. SOOOO theoretically without the outside air flowing through my AC duct I should have a good sleep tonight. I love how that if I have a problem such as a Backdraft on my AC Duct that I could find it on Amazon.

nice ,it works.

Exactement ce que je cherchais

The flaps would rub against the bottom of the damper. I wrapped a paper clip around the bottom part of the rod to make a washer and cut off the excess. This raised the flaps high enough so they no longer rubbed. The damper must be installed with the flaps oriented vertically (like a door). When connecting the damper to the duct work, the crimped end off the existing duct will not fit into the damper so the crimp needs to be cut off and the damper will slide into the duct. When installing a sheet metal screw, there's no issue on the supply side but on the exhaust side the screw must be either at top dead center or bottom dead center so it will not interfere with the flaps opening. Once installed, the damper worked great and stopped the cold outside air from entering the stove exhaust.