+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 10 of 12
  1. #1
    Join Date
    Dec 2009
    Posts
    3

    Default 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!

  2. #2
    Join Date
    Dec 2009
    Posts
    3

    Default Re: Installing New Bath Vent Fan and ducting

    Anyone? Anyone? anyne out there?

  3. #3
    Join Date
    Jun 2007
    Location
    Fayette County, Ohio
    Posts
    5,842

    Default 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
    Be sure you live your life, because you are a long time dead.-Scottish Proverb

  4. #4
    Join Date
    Dec 2009
    Location
    Casper, Wyoming
    Posts
    159

    Default 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

    ___
    Find professional plumbers in your area

  5. #5
    Join Date
    Apr 2009
    Posts
    158

    Default Re: Installing New Bath Vent Fan and ducting

    Quote Originally Posted by JLMCDANIEL View Post
    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.

  6. #6
    Join Date
    Jun 2007
    Location
    Fayette County, Ohio
    Posts
    5,842

    Default Re: Installing New Bath Vent Fan and ducting

    Quote Originally Posted by peterbouchard View Post
    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
    Be sure you live your life, because you are a long time dead.-Scottish Proverb

  7. #7
    Join Date
    Apr 2009
    Posts
    158

    Default 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?

  8. #8
    Join Date
    Jun 2007
    Location
    Fayette County, Ohio
    Posts
    5,842

    Default 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
    Be sure you live your life, because you are a long time dead.-Scottish Proverb

  9. #9
    Join Date
    Dec 2009
    Posts
    3

    Default 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.

  10. #10
    Join Date
    Dec 2007
    Location
    MN
    Posts
    455

    Default 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.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •