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Dryer Vent Insulation

Post in 'The Green Room' started by Vic99, Jan 20, 2012.

  1. Vic99

    Vic99 Minister of Fire

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    I have insulated the clothes dryer flex pipe with insulation made from recycled blue jeans (R5). The vent has a flap that closes properly when the clothes dryer is not in use. It is caulked and installed properly. See stock photo.

    Problem is on cold days I still feel a pretty good draft near the dryer. Any other options for sealing that area up better?

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  2. ecocavalier02

    ecocavalier02 Minister of Fire

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    Not really unless you want to plug it with insulation and remove it every time. your not really loosing that much heat. should be fine.
  3. velvetfoot

    velvetfoot Minister of Fire

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    I did a similar thing. My dryer is right next to an outside wall, so I put a hole through the wall and covered the short run with fiberglass. I don't recall caulking the opening, but I think I did. :) . That might be where your air is coming in. I think I have a better vent than you do: I don't have a picture, but it is round and makes a good seal. Even if the dryer door is closed, I wonder if cool air, maybe being sucked in by general negative house pressure at this time of year, could escape from the dryer and cool the general area.
  4. Frozen Canuck

    Frozen Canuck Minister of Fire

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    Vic there is a model of dryer termination vent that solves this common problem, sorry can't recall the brand name so I will describe it. Essentially it is a foam ball in a rack that runs on a slight uphill angle, when the dryer is turned on it blows the ball to the end of the rack allowing the dryer to vent, when the dryer shuts off the ball rolls back downhill to seal the hole. Positive gravity assisted seal. Works far better than any flapper type that are prone to cross drafts/winds opening them or freezing open after use. If I can remember the name I will post it here.

    BTW you are dumping a lot of heat, the reason this 4" hole in your wall is ignored by so many is that it is an out of the way place that really gets little attention, the laundry room. The same 4" hole in your living room or kitchen or entry door where occupants could feel the draft would be dealt with immediately.

    P.S. That flex pipe you speak of is going to trap a lot of lint, nature of the beast I am afraid. When time allows think about replacing it with straight pipe.
  5. nate379

    nate379 Guest

  6. Vic99

    Vic99 Minister of Fire

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    Dryer is on main floor behind folding doors in a study nook. Baby plays here sometimes.

    I thought about cutting polystyrene foam to cover, but too much of a hassle. Then I thought about using a heavy duty zip lock bag, double bagged. I'd fill it with toilet bowl wax, sealing the bag and form fitting it over dryer vent opening on outside of house. Would have to test to see if it freezes first, but would be a pain to remove each time.

    Instead I will look into that new dryer vent cap. Thanks.
  7. DickRussell

    DickRussell Member

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    The vent device in the link Nate provided also is known as the Heartland 21000; I'm not sure who the mfg is. Anyway, it is an excellent choice for the purpose. Under the top (removable for cleaning) cover is a plastic shuttle that floats up on discharge air pressure. The air comes up, reverses direction outside the pipe, and exits to the outside underneath the body of the device. When the dryer turns off, the shuttle settles back down over the discharge pipe opening to close it off. I bought one for use in the new house and have been pleased with it. A year ago, during the first blower door test, I forgot that the dryer pipe still was unconnected at the dryer end and thus totally open to the inside, until near the end of the test. I put my hand to the open end and couldn't feel any of that cold January air coming back through, despite the depressurization of the house to the standard 50 pascals below outside pressure.

    Edit: I also contacted Heartland to see if they made a 6" version of it, for use as a vent for a range hood, but they replied that the 4" version was the only one, so I went with a Broan 639 rectangular vent cap, which is a sturdy device that seems to close off fairly well.
  8. semipro

    semipro Minister of Fire

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  9. nate379

    nate379 Guest

    I wonder if those work decent with bath fans? Mine freeze shut when it gets in the negative temps. They open up after the fan is running for a bit, but it's annoying if I want to get the stank out of the bathroom WHILE it's being made haha.
  10. semipro

    semipro Minister of Fire

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    Ours is installed in a half bathroom so it doesn't see the moisture a full bath does.
    I assume yours gets wet while venting and then freezes up when it closes?
    I guess that could be considered a good thing as it probably means you're not leaking a lot of heat out that way.
  11. Vic99

    Vic99 Minister of Fire

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    Ordered a heartland. Hope to install it this weekend and report back. If it fails maybe there is another issue, but the whole wall and floor of that room was spray foamed to R-21+ with closed cell.
  12. Slow1

    Slow1 Minister of Fire

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    Good thoughts here. Our dryer is in the bathroom on main floor and room is always pretty cold in the winter. We don't use the dryer much at all, I wonder how much cold air comes in through the vent... I'll have to look into alternative vent covers....
  13. greythorn3

    greythorn3 Minister of Fire

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    make your wife sew one up.

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