neverestRKI 8 inch Professional Backdraft Damper Stainless Round Steel Inline Spring Loaded Durable for Dryer Duct - Fits Only with Metal Ducts

Bought this to keep cold air from coming into my woodshop and it works great.

No more opening the dryer to freezing cold clothes on winter days. This was super easy to install and has worked well for a whole year with one maintenance cleaning. I am going to install one for the kitchen hood vent as well.

My house has several exhaust vents, so air being sucked through my dryer vent while my hvac is running has been a battle. I would find condensation in my dryer drum on hot days due to the standard backflow valve that is installed on most exterior venting dryers being insufficient.This backflow valve slipped right into the back of the exterior backflow vent duct and has been there for over a month now, no consequence to dryer performance. It appears to be of a good build quality, seals well, and is of an excellent value. My dryer duct is a standard size, this will work in most homes. I dont recommend it be installed on the dryer side of the duct as the rubber may deteriorate due to heat.

I bought this to help keep some of the cold air out of my laundry room when the dryer is not in use. It's a very tight fit in my 4 inch vent pipe. I had to remove the black seal for it to fit.

The damper in our shower was all but non-functional. Any time the wind was blowing the damper would open both ways creating a constant inflow of cold air into the shower. The airflow on the existing fan was strong but not easily accessible. I ended up going to the exhaust vent in the soffit, removing it and adding this product directly at the outlet above the webbed vent. It was easy to install with duct tape and inserted into the existing 4 inch flexible tubing. The damper is designed such that it can't open from the exhaust side and it doesn't take a significant amount of pressure to open it. Now the strong winds that blow against that side of the house have met their match! I plan to add the 6 inch version to our cooktop exhaust.

Used this device to prevent backdraft coming into my house through my dryer exhaust vent (I could use my dryer and laundry area for cold storage during winter, the draft was that bad at times).Since my dryer vents through the roof rather than the side of the building I needed something that could be installed horizontally and in line, requiring little force to open when in use due to the horizontal orientation. This certainly did the trick.Sturdy frame yet lightweight shutters that open easily while in use, remaining sealed otherwise. The mechanism is assisted by a small spring that ensures shutters remain closed regardless of orientation and backdraft (the spring is probably not needed in a horizontal install but provides a bit of extra support to prevent any flapping and is probably quite helpful should the device be installed vertically). The rubber ring ensues a tight fit/seal within the ductwork.Air pressure needed to force shutters open is minimal, which alleviated any concerns I had about it not allowing exhaust air to vent properly.

Super clever device! Couldn’t be easier to install and works like it should. We had a bad back draught from the outside air. It was ridiculous! Got this installed inside 5mins! Fantastic!

A good product out of the box, thin aluminum flaps and three light spring is are the only mechanical parts on this one. Works as expected, the main cylinder is built sturdy, this is my initial experience looking at the product and testing the flaps and how the springs actually handles the thin aluminum flaps to close up. Rubbed gasket ensures air tight seal and prevents backdrafts.Will update when I get to install the product later on.