# Dryer vent backdraft damper



## BlueCrystalMan (Jan 1, 2010)

My dryer vents through the wall through a crawlspace to an outside wall. I replaced the 15 year old venting today... In the process, I added a Deflect-O Back Draft Damper... It is heavy duty plastic... I mounted it on the wall where the dryer vent leads into the crawlspace... this damper is about three feet from the dryer.

My question is... with it being plastic, is this a problem with the heat from the dryer? Doesn't seem to be an issue, even though the hose clamp holding the dryer vent to it is quite warm.

Thank you.


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## Gary in WA (Mar 11, 2009)

Take it out, do not use it. It will stop and collect lint leading to clogging and a *possible fire hazard*.

The backdraft damper is required to be at the *duct termination* for dryers. 

The pipe should be* smooth metal inside* with the male ends of pipe facing direction of air-flow. (NO plastic, NO obstructions)

*No screws* permitted and* 4"* minimum size required as per code. 

Use an "A type" door, 50% more airflow: http://www.appliance411.com/faq/dryer-vent-length.shtml


http://www.hcpdc.com/pdf/Dryer Vent Requirements.pdf


http://docs.google.com/viewer?a=v&q...X-cV2r&sig=AHIEtbRqP1_bx_SQclGLup65cYgFwMvULw
Be safe, Gary


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## BlueCrystalMan (Jan 1, 2010)

Excellent post, Gary. Thank you!

What is your recommendation for getting the duct through the wall, then? Just run it straight through and insulate around it? Or use some sort of connector that fastens to the wall (much like this damper does)?


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## COLDIRON (Mar 15, 2009)

Go to HD or LO___ and purchase a dryer vent with the damper already attached drill the hole install the vent then pipe up to and into it with the 4" pipe from the dryer. Make sure the pipes are facing the proper direction and they are taped tight.


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## Gary in WA (Mar 11, 2009)

I would run straight smooth metal pipe, with 45* elbows (unless close to the max. on elbow deductions) right through the crawl door/plywood. Oversize the hole, add metal tin pieces (overlapping at center circle cutout), use Type A hood with aluminum foil tape at all joints, including each individual elbow. If a gas exhaust also, follow codes sited- 3' from openings, etc. Don't forget to use stainless steel flex hoses on the water supply to the clothes washer (no burst). 

Be safe, Gary


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