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kennybat
Installing New Bath Vent Fan and ducting

Looking to tackle the project of adding ventilation to my bathroom. My concern is where and how to run the duct. Some have said through the roof is the only way to go and others say out of the side of the attic. I'm not afraid to go through the roof however if I can avoid it that would be great. My concern is the length of the run from the fan housing to the side of the house is around 15 ft. Can anyone tell me if that is to long of a distance to run the duct? Also someone else mentioned taping in to the plumbing vent that exits the roof very close to where the fan would be placed. I don't think that would be wise because of sewer gases. Any help on this one is appreciated. Thanks!

kennybat
Re: Installing New Bath Vent Fan and ducting

Anyone? Anyone? anyne out there?

JLMCDANIEL
Re: Installing New Bath Vent Fan and ducting

Through the roof is always best. It can be out the side but never under a soffit with vent-holes or the warm moist air will rise back into the attic.
Jack

Re: Installing New Bath Vent Fan and ducting

Through the roof is the best way. Through the attic often results in condensation on the fan (due to the change in temp. from the bathroom and the attic), and you don't want to have water droplets dripping from the fan onto your bathroom floor. 15 ft. doesn't sound too long to run the duct but I always say, better safe than sorry- you may want to ask a plumber or roofer or even check with the staff at a home improvement store (or see if you get more responses here :)

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peterbouchard
Re: Installing New Bath Vent Fan and ducting
JLMCDANIEL wrote:

Through the roof is always best. It can be out the side but never under a soffit with vent-holes or the warm moist air will rise back into the attic.
Jack

Interesting. I was wondering if this was my problem. I did just what you said, and I did have issues as you talk about. I wasn't sure if it was that I used hard ducting and needed to seal/tape the elbows or if air was making it back into the attic as you suggest. I've disconnected it as soon as I noticed the issue. Now ill have to decide to go thru the roof or thru the side, which is a good 15 ft.

JLMCDANIEL
Re: Installing New Bath Vent Fan and ducting
peterbouchard wrote:

Interesting. I was wondering if this was my problem. I did just what you said, and I did have issues as you talk about. I wasn't sure if it was that I used hard ducting and needed to seal/tape the elbows or if air was making it back into the attic as you suggest. I've disconnected it as soon as I noticed the issue. Now ill have to decide to go thru the roof or thru the side, which is a good 15 ft.

An easy test is to extend the duct out past the soffit. Looks bad but would prove the point.
Jack

peterbouchard
Re: Installing New Bath Vent Fan and ducting

The reason I installed the fan was because I noticed mold above the bathroom on the attic ceiling (roof). I cleaned it up and installed the darn exhaust fan...at the same time put better venting in the soffit area. I bet I would have been fine with just adding the vents. I don't think enough air was getting into the attic.

thoughts?

JLMCDANIEL
Re: Installing New Bath Vent Fan and ducting

Warm moist air escaping up through a ceiling fixture box will hit the cold sheeting and condense. A certain amount may also migrate through the drywall, and work its way up through wall cavities rise and condense.
Jack

kennybat
Re: Installing New Bath Vent Fan and ducting

Thank you for the responses everyone. My next question is if I go through the roof with a standard roof vent how will the snow affect the vents ability to exhaust the air? Here in Ohio we can get quite a bit which would cover the vent completely.

bsum1
Re: Installing New Bath Vent Fan and ducting

Lots of folks vent through the roof but we did ours through an end wall in the attic. We don't have any problems with freeze ups unlike the other folks that have them on the roof.

JLAMBERT04
Re: Installing New Bath Vent Fan and ducting

my husband and I had been wondering how to do the same thing. Our bathroom on the first level of our home has no vent and so unless we leave the window open the bathroom gets no ventilation. How would we go about adding a vent in a middle room of our house? I would hate to send the vent up through the floor of the room above it and up through the attic and out the roof, could we cut a hole through the wall of the bathroom and through the brick and place the vent on the wall of the house. It would look weird but I, myself can't think of any other way. Anyone have any suggestions for this?

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