(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 15 of 28

Thread: Code for Dryer Venting

Hybrid View

  1. #1
    DIY Senior Member molo's Avatar
    Join Date
    Sep 2006
    Location
    cold new york
    Posts
    840

    Default Code for Dryer Venting

    I am installing a gas dryer and would like to know if I can vent it down through the floor and out a basement window. Any ideas?

    Thanks for any replies
    "Any American who is prepared to run for President should automatically, by definition, be disqualified from ever doing so."
    Gore Vidal.

  2. #2
    Retired Defense Industry Engineer jadnashua's Avatar
    Join Date
    Sep 2004
    Location
    New England
    Posts
    21,401

    Default

    Not sure about codes, but you'd have a big problem if there was a leak, plus, I think you'd end up decreasing the efficiency by maybe a significant amount...hot air wants to rise, not be pushed down. Plus, if there was a leak, you could have CO, too. Having it rise, like in a flue, is both safer and more efficient.
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

  3. #3
    DIY Senior Member molo's Avatar
    Join Date
    Sep 2006
    Location
    cold new york
    Posts
    840

    Default

    Quote Originally Posted by jadnashua View Post
    Not sure about codes, but you'd have a big problem if there was a leak, plus, I think you'd end up decreasing the efficiency by maybe a significant amount...hot air wants to rise, not be pushed down. Plus, if there was a leak, you could have CO, too. Having it rise, like in a flue, is both safer and more efficient.

    This would be in a flu pipe (rigid) but it would go downwards about 2 feet and over about 5' before exiting.

    Thanks for any replies
    "Any American who is prepared to run for President should automatically, by definition, be disqualified from ever doing so."
    Gore Vidal.

  4. #4
    Plumber jimbo's Avatar
    Join Date
    Aug 2004
    Location
    San Diego
    Posts
    9,001

    Default

    Actually, I don't see a code issue with dropping down and over. True that heat rises, but air has mass, and can be pumped down more easily than up. Efficiency will not be affected.

    Just exactly how you terminate needs to be worked out. You don't want moist air backfeeding into the basement through that window, or collecting in a poorly ventilated space.

  5. #5
    DIY Senior Member molo's Avatar
    Join Date
    Sep 2006
    Location
    cold new york
    Posts
    840

    Default

    Quote Originally Posted by jimbo View Post
    Actually, I don't see a code issue with dropping down and over. True that heat rises, but air has mass, and can be pumped down more easily than up. Efficiency will not be affected.

    Just exactly how you terminate needs to be worked out. You don't want moist air backfeeding into the basement through that window, or collecting in a poorly ventilated space.
    If this will work. I will probably eliminate the small basement window entirely to terminate the vent through.
    "Any American who is prepared to run for President should automatically, by definition, be disqualified from ever doing so."
    Gore Vidal.

  6. #6
    Senior Robin Hood Guy Ian Gills's Avatar
    Join Date
    Jul 2007
    Location
    USA
    Posts
    2,781

    Default

    I installed a dryer vent window. So far so good.


  7. #7
    In the trades Dana's Avatar
    Join Date
    Jan 2009
    Location
    01609
    Posts
    2,720

    Default

    Quote Originally Posted by jimbo View Post
    Actually, I don't see a code issue with dropping down and over. True that heat rises, but air has mass, and can be pumped down more easily than up. Efficiency will not be affected.

    Just exactly how you terminate needs to be worked out. You don't want moist air backfeeding into the basement through that window, or collecting in a poorly ventilated space.
    A few errors in physical intuition model here...

    *Heat doesn't rise, it moves from hot to cold.

    *Less-dense fluids rise as denser fluids fall due to gravity. Hot exhaust gas has lower density than cold exhaust gas (or air), and will rise as the denser gas displaces it due to gravitational forces. (The cloud of less dense gas "floats" in the denser gas, rising.)

    *It takes more energy, not less, to force a lower density gas downward, counter to the gravitational forces on the denser cool gases that it is displacing. (It's "easier" to pump it up, working with gravity.)

    Thought experiment: Take a helium balloon at head height, push it to the floor, what happens? You've forced an equal volume of heavier gas (the air) upward against the force of gravity- that takes energy.

    In the dryer vent gas case it's not a huge force if the drop is small, say 3-5', but at 20' you may encounter measurably lower flow (and not just due to duct friction.)

    Can't help on the code issue though- no idea.

  8. #8
    Homeowner Thatguy's Avatar
    Join Date
    Aug 2008
    Location
    MD
    Posts
    1,460

    Default

    http://www.oddcast.com/demos/tts/tts...le.php?clients

    J'espère que vous apprécierez votre séjour ici

Bookmarks

Posting Permissions

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