# Backdraft Damper For Dryer Duct



## tima2381 (Feb 24, 2007)

I need to install a backdraft damper at the end of my dryer duct. Any recommendations? The Aldes BDD4 advises not to use it for dryers. Maybe the Fantech RSK4 would be OK?

For your amusement, here's what I found when I investigated why my dryer wasn't working too well in my 3 y/o house. I found the end of the duct screwed into the roof sheathing, and when I unscrewed it, here's the beginning of what I pulled out:










I proceeded to remove a grocery bag full of lint, feathers, and twigs, and I was very excited to have solved my problem. Alas, when I tried to screw it back to the roof, the entire segment came off in my hands:










This had been previously sort of attached to the duct exiting the wall space:










As you can see, instead of using a proper 90deg elbow, the sociopath who installed the thing cut a pipe at about a 45 degree angle and loosely taped it to the vertical pipe, which explains some of the lint and excavation I found nearby in the insulation. I guess he figured the airflow reduction would be mitigated by the poor seal he achieved. No, wait, that's stupid. The jerk clearly didn't give any consideration to the performance, longevity, or correct operation of the thing. So I had a very fun couple of afternoons fixing this in the very cramped space I had to work in. (No, I didn't reinstall the piece of junk pictured above; I did it right.) Best thing I bought was a 2x4' piece of MDF to lay across the joists, which was a lot easier on my stomach than lying on the joists directly.

Anyway, the vent cap is just a short piece of pipe with a hood over it to keep out rain, open on all sides but the top. It has no damper, hence my question.


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## PaliBob (Jun 11, 2008)

Thanks for posting the pics:thumbsup:

ASHI (American Society of Home Inspectors) publishes a newsletter that has an applicable article on Dryer Exhaust Systems


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