4 Inch Draft Blocker Backdraft Damper Duct Draft Stopper One-Way Airflow Ducting Insert Backflow Preventer Inline Fan Vent Deflector

WELL CONSTRUCTED, SHOULD WORK PERFECT

Wasnt avail at big box stores near me so I scrambled to order this for my contractor installing the ductwork for my new kitchen stove vent. He said it was perfect and easy to install. It seems to be working great and our city inspector specifically went out of his way to check it. Passed without issue. Recommended.

Stops outside air from coming into the dryer. Easy to install, ensure you get the airflow direction correct.

Although the documentation said it would work in a vertical installation, that didn't work for me. The spring controlling the damper blades was too strong and it barely opened when my 250 CFM range hood was on high speed, using 6 inch stack ducting. I used some snippers to cut the spring out of the damper and just rely on gravity to close the two doors and it worked perfectly. The housing is rigid enough to maintain its round shape to prevent binding of the damper doors. It has some foam strips which help the doors seal very nicely.

Works well and open completely with a over the range microwave hood.

I read the lower than 3 star reviews before I purchased and I purchased anyway. Of course there was no instructions but I’m familiar with these things. This damper needs to be installed in the correct orientation. Hinged doors open to the outside. It needs to be connected to the existing 4” exhaust pipe with foil tape (ensure no leakage) on both sides with the spring hinge in a horizontal or vertical position. If you follow those simple rules this thing works great! My 50 CFM fan moved air with no issues and there is no air from the windy outside pushing back into the house. I would say that the closer you install this damper to the outside damper that is attached to your house, the better your results. I would buy this again. Correct installation is everything.

Each time the A/C or furnace kicked on it would draw outside air in through the vent hood. Cold in the winter and hot in the summer. The temperature under the hood was significant and very noticeable. So I installed this draft blocker in the pipe in the attic, separating the pipe at a joint inserting the valve and reconnecting the pipes. I seal the joints with aluminum tape. The draft blocker has a weather strip inside sealing it when not in use. I did have to reseal the pipe where it passed through the roof with roof tar to restore the water seal. It works great, the is no back draft now when the A/C is running and made a huge difference. I would recommend and buy again.

Great product. Great seller. Fast delivery. Product was as described. Will definitely recommend

Exactly what I ordered and delivered the next day. Installed it and works perfectly.

Je suis très satisfait

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.

Awesome little Backdraft pipe 4-in adapter even has a little bit of air support so it doesn't push through the cracks with the liner inside the pipe

I used this to keep the cold from coming into the house throught the dryer vent. It works great, and was easy to install. It has a foam seal instead of the hard rubber ring that another one I purchased on Amazon at almost double the price had (I returned that one because I could see daylight between the flaps and the rubber "gasket"). I deducted a point because the foam seal was not installed accurately, but Iwas able to adjust it fairly easily. The manufacturer need to take more care assembling these, as the whole point is to not have cold air leak padt it.