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walkerbe · Sep 28, 2011, 08:28 AM

I have a single level home and the dryer venting goes straight up through attic approximatley 20 feet of pvc (green) pipe it condensates on the pipe and is starting to ruin the drywall ceiling (where it comes in the house at ceiling)

twinkiedooter · Sep 28, 2011, 08:38 AM

Dryer vents need to have the shortest possible route to the outside. The vent should have been vented to the nearest possible outside wall. You will continue to have the excess moisture in your attic until you relocate the dryer vent to the outside wall.

walkerbe · Sep 28, 2011, 08:47 AM

Unfortunately my washer/dryer is located dead center of my home and it's a distance any way I go to vent this. That's why I went straight up

twinkiedooter · Sep 28, 2011, 08:57 AM

You need to figure out a way to vent the dryer directly outside or the moisture problem will only continue.

walkerbe · Sep 28, 2011, 09:30 AM

It vents directly outside > Straight up approximatley 25 feet this is from the floor to peak of roof and out about a foot outside

twinkiedooter · Sep 28, 2011, 09:40 AM

The only other solution would be to heavily insulate this pipe but I would suggest a metal pipe and not a PVC pipe like you have.

Of you could get one of those box like contraptions that send the heat from the dryer into the actual room with a filter keeping the lint particles out of the air. That would only force all the moisture into your home.

parttime · Sep 28, 2011, 09:51 AM

Try this walker, https://www.hvacquick.com/howtos/howto_dryer.php

Good luck

hkstroud · Sep 28, 2011, 11:28 AM

Moisture from condensation should not be occurring as you describe it. Condensation occurs when warm moist air comes into contact with a cold surface.
Are you sure that you do not have a roof leak where the piping goes through the roof.

If the moisture is indeed being created by condensation it should not occur in the attic above the ceiling. The attic air temperature should approximately equal the air inside the pipe which entered the pipe from the exterior.

Condensation could conceivably occur during the winter months if the warm air inside the house comes into contact with the pipe which has been cooled by air inside the pipe from the outside. That could only occur if the pipe is expose to the interior warmer air. One solution would be to insulate and enclose the pipe.
Another solution would be to install a vent cover with a damper that would prevent cold air from entering the pipe. You can probably find such cover in the ventilation section of Home Depot or Lowe's. You may be able find a damper that would fit in the pipe in the attic and not have to go up on the roof. You would most likely be able to find that at a heating supply.

The objective being to stop cold air from entering the pipe below the ceiling yet is opened by the pressure of the dryer exhaust .

drtom4444 · Oct 1, 2011, 02:52 PM

Vent straight down if that is possible or move drier. You cannot vent a drier up without a booster fan or two or three. You need at least two booster fans and still lint will build up on the walls of the vent. What is the diameter of the PVC? It would need to be at least 4 inches and that is not cheap. I would move the drier. You probably need to tear down the drier and clean it out, too, because when it has been running in that condition you can bet the lint build-up is thick inside and cutting down on airflow. That blower in the drier is not meant to move the exhaust more that about 4 feet. DrTom4444