Plumbing in the Home/Dryer Vent


Dear Dana,

Can you tell me why I have two dryer vent inlet; one three inches off the floor, the other about thirteen inches off the floor, and direct above the lower one. They both share the same vent behind the drywall, which goes up through the roof. Is it possible that one vent inlet is designed as an access hole for cleaning so that the connection to the dryer doesn't have to be disconnected? Is there a proper way to cap the spare vent (right now, the lower one has tin foil over it)? Is it better to use the lower or upper outlet? (I imagine it's best to connect to the upper one, so the lower one can act as a trap for falling lint).

I've searched all over the web for an answer to this. Is it possible that the contractor just screwed up and put in the second inlet to correct his mistake?

Your advice will be appreciated.



Hi Joe,
You may be right about the clean out or the mess up!  I've never seen this done.  No reason for a second vent pipe that I know of. I'm not aware of any standard cap for this type of pipe. There is typically no reason to cap it off.  You might need to get creative for the cap. I would think foil would be a bit fragile and easily damaged but it is sort of out of the way back there so maybe not an issue.

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Dana Bostick


Pretty much any residential plumbing questions. For "item specific" details such as a specific model of fixture, I will need to research and there may not be any useful information available. Note: I live and work in Southern California. We do not, as a rule, use hot water or steam heating systems, oil fired boilers or private water wells so my knowledge in those areas is pretty limited. There are others here on AllExerts that can probably answer those questions better.


Retired, Licensed General Contractor with Plumbing license. Active Home Inspector, Litigation Consultant and Infrared Thermographer, Online Marketing specialist.

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