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AC Infinity

AC Infinity Backdraft Damper 6" One-Way Heavy-Duty Airflow Ducting Insert

  • Based on 2,056 reviews
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Availability: In Stock.
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Arrives Sep 17 – Sep 18
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Size Name: 6 Inch


Features

  • An antidraft duct insert designed for use with range hoods, bathroom fans and other home HVAC applications.
  • Features outer rubber gaskets that create an airtight seal and grip between the damper and ducts.
  • Mounts horizontally or vertically to prevent backflow and debris from entering ducting.
  • Galvanized steel body with spring-loaded aluminum damper blades that open with minimal airflow.
  • Fit for 6 in. Duct Openings | Product Length: 5.03 inches | Finish: Powder Coat

Description

Product Description A ventilation ducting tool designed for insertion into ducting to prevent cold drafts and debris from flowing into ventilation systems. Built to be embedded in ducts, the backdraft damper is made of sturdy galvanized steel and features two rings of outer rubber gaskets. This enables it to grip your ducting with an airtight seal in either a horizontal or vertical orientation. The butterfly damper blades are made of aluminum and are equipped with a light spring that folds with minimal airflow. Applications The spring-loaded antidraft damper is built for heavy-duty performance in applications like overhead range hoods in kitchens, bathroom fans and tumble dryers. It can be fully or partially inserted into your duct work using the rubber rings to hold itself in place. Other one-way airflow uses include keep pilot lights burning in water heaters and keeping debris from entering inline duct fans in grow tents. A one-way airflow duct tool designed to prevent exhausted air and odors from sweeping back into ventilation systems. In any air delivery system, residual air that lingers can drift back into the area you want to keep clean. This wastes the efforts of your high-powered fan, forcing you to run it longer and increase your energy use. The backdraft damper is everything you need to ensure air and odor flows in one direction and keep your space well ventilated. The lightweight shutter blades are made of aluminum and easily open to airflow. Spring-loaded to close when your fan is turned off. Once the butterly blade dampers are closed shut, they block exhausted air and odor from flowing the other way, ensuring full ventilation. Outer rubber gaskets line the backdraft damper to provide grip on your inner duct lining. Allows you to install it in horizontal or vertical orientations. A sleek body that is crafted with galvanized steel and finished with black powder-coated paint. Offers a strong build with aesthetic looks. AC Infinity is a technology company that specializes in environmental controls for audio/video and HVAC. The company was founded on the principle of working closely with customers to develop great products. Dependable service and a commitment to product quality are the foundations of the business's values.

Size: 6 Inch


Material: Alloy Steel, Aluminum


Brand: AC Infinity


Color: Black


Item dimensions L x W x H: 5.12 x 5.79 x 2.28 inches


Connector Type: AC Power Plug


Item Weight: 1.3 pounds


Number of Pieces: 1


Number of Packs: 1


Global Trade Identification Number: 10


Brand Name: AC Infinity


Number of Pieces: 1


Model Number: AC-BDD6-B


Number of Packs: 1


Global Trade Identification Number: 10


Manufacturer: AC Infinity


Unit Count: 1 Count


UPC: 819137021310


Included Components: Backdraft Damper


Manufacturer Part Number: AC-BDD6-B


Size: 6 Inch


Item Dimensions: 5.12 x 5.79 x 2.28 inches


Item Weight: 1.3 pounds


Connector Type: AC Power Plug


Material Type: Alloy Steel, Aluminum


Item Highlight: Antidraft Duct Insert w/ Airtight Seal & Spring-Loaded Aluminum Folding Blades for Ducting in Range Hoods and Bathroom Fans


Color: Black


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sep 17 – Sep 18

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews

    • Wicked durable and very well-made
Size Name: 6 Inch
The quality and durability of this Backdraft preventer is quite frankly amazing. This is my second one that I have bought, and the quality and durability is more than I would’ve desired. Buy another brand at your own peril if you want things to work
Reviewed in the United States on September 8, 2026 by Meticulous
    • Great company, great products
Size Name: 6 Inch
Review Image by 玄衡
Review Image by 玄衡
Review Image by 玄衡
After reading through dozens of reviews and product information, we first bought the AC Infinity Flexible 6-Inch Aluminum Ducting, Heavy-Duty Four-Layer Protection, 8-Feet Long for Heating Cooling Ventilation and Exhaust. It was packaged so well you could send it as a Christmas gift, the quality of the duct tubing was outstanding. Fast forward a week while we were installing the new stove exhaust fan, we realized we would need this flapper piece, as the old one was getting stuck. We were so impressed with the duct tubing that we purchased this product from AC as well, and were not disappointed. It is the Mercedes of exhaust flappers. This AC flapper was the exact size advertised at 5.79" width/diameter, which was just a smidgen smaller than most of the others advertised at 5.90" diameter. So instead of having to monkey around with it, it slipped perfectly inside the Vikio range hood 30" under cabinet kitchen hood with 980 CFM, 3 speed gesture sensing & touch control panel in stainless steel, vent hole on top the hood. A little larger it would not have worked, we are grateful the AC specs are perfect, it made the install a dream come true. I do agree with another review I read, in that the AC 6" ducting is a tight fit on their own product/flapper, although I got it to slip on, it was as tight as could be without being unworkable, but the bottom line is it went on. And it slipped over the existing 6" coupling tube to the roof perfectly. We will keep this company in mind when doing other projects, such as heating, vents, dryer etc, well worth the cost. Thank you ... show more
Reviewed in the United States on March 6, 2025 by 玄衡
    • Quiet; large; spring-loaded; very well made; FINALLY WORKS
Size Name: 8"
If I could give it 6 stars, I would. This is my FOURTH go around at trying to solve a backdraft problem with my kitchen vent hood. This one finally did the trick. Amazing how many bad options there are out there for a backdraft damper, never would have guessed it. The problem is that most other backdraft preventer work by closing the flap using gravity alone, and it turns out that once installed, that's not always enough - kind of random. But you can tell right away when you step in the kitchen if the flap is open or not by whether youre freezing or comfortable: Walk to the hood; put your hand under and feel for the draft; get your answer - you'll always guess it right. With this one, it's always closed and the room is always comfortable. Thank you thank you thank you!! It's also very well made (sturdy, compared to all the others) and _not_ more expensive! It's also quieter than the others. Go figure. My only complaint: it only comes in 6" or 8" dia. WTF!! A vent hood has standard 7" ductwork. I got around this by buying and installing 2 flares, one on either sides. It mates nicely with the 7", but you need to have a bit of room in the cabinet above the hood: can't have a 90deg turn too close to the hood. You won't be able to cut through the metal work to reshape it easily, unless other thin-gage dampers, which I spent hours re-shaping. Works like a charm when installed right. ... show more
Reviewed in the United States on March 20, 2025 by Patrick Lemieux
    • Great product.
Size Name: 8"
Review Image by Jack jack
Review Image by Jack jack
Quality is great, and worth the purchase. I wish it was a bit lighter like 3d print
Reviewed in the United States on January 12, 2026 by Jack jack
    • Great quality and did the job
Size Name: 4"
AC Infinity stuff is always great, this is no exception. I’ve got two of these hooked up in the attic so I can run two exhaust fans to one outlook. They lit the air flow freely, but only in the direction I want. Allows me to pass code! Nice product, easy install and since it’s in the attic no perceived noise inside (I don’t know if it’s load next to it). Good value! ... show more
Reviewed in the United States on May 24, 2026 by James Mercer
    • Works but not recommended for low airflow/passive systems
Size Name: 4"
I needed to create an exhaust system for my 3D printer so I purchased the AC Infinity cloud line in-line fan along with this backdraft damper since my exhaust leads directly outdoors. One thing I noticed is that the springs on this damper are pretty stiff so it requires a decent amount of airflow to push the damper flaps open. Using the cloud line S4's speed controller as a reference, the flaps didn't open until I got to level 4. The reason this may be an issue is because in temperature controlled environments (like printing certain types of material) you don't want your in-line fan to be too strong otherwise it will cool your chamber too quickly. Aside from that, the damper is constructed well and will likely last a long time. One other thing to note, I bought the 4" damper and with 4" ducting it is a very tight fit to get the ducting around so it does create a decent enough seal. Overall works well but if you only require a low airflow system like me I would recommend testing this out first before fully installing. ... show more
Reviewed in the United States on November 10, 2025 by Mad Mensch
    • Spend the extra 5 bucks!
Size Name: 6 Inch
Works perfectly! Not too easy to open that it's flopping around but easy enough a light push my from acinfinity fan vents all these spores outside!
Reviewed in the United States on March 20, 2026 by Zach
    • The damper works like it should
Size Name: 4"
I was concerned that the springed baffle would be too stiff. It was not and I am pleased with this damper
Reviewed in the United States on August 30, 2026 by Larry Daniels

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