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Venting small freestanding stove under 30" windows?

Post in 'It's a Gas!' started by UncleLongHair, Aug 3, 2008.

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  1. UncleLongHair

    UncleLongHair New Member

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    I'm considering installing small stove (wood or gas, probably gas) in living room. The room has windows all around it about 30" off of the floor. My idea is to vent the stove horizontally under the windows.

    I've been looking at the installation guides for the smaller stoves (i.e. Jotul GF 100), and it looks like they might fit. They say that there has to be 9-12" of clearance (depending on the power of the stove I guess) between any flue components and windows. Some of the smaller stoves are 20-22" high, the vents in the back are 15-20" at their highest point, and "on paper" this seems to fit. Then on the outside, they have different kinds of caps, but the ones for the smaller stoves would fit.

    So this seems like it would be possible, but I can't find any examples of this online, and talked to the sales guy at a local stove store and he said he wasn't sure. Any help appreciated.

    Uncle

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  2. lugoismad

    lugoismad New Member

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    To the best of my understanding, any solid fuel wood burning device HAS to be vented vertically.

    The chimney needs to come out of your roof, and be 2 foot above anything within 10 feet of it.
  3. UncleLongHair

    UncleLongHair New Member

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    Well I've seen pellet stoves with horizontal vents, and I'm looking at gas fireplaces primarily and many of them seem to be able to be vented horizontally.

    Uncle
  4. R&D Guy

    R&D Guy New Member

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    I believe 12" is the old ANSI Z21.88 standard. They updated the clearances around 2005 and a lot of them are closer than before. Could be Jotul did their own testing and found it needed to be father away on some units, but what's more likely is that the unit was put on the market before 2005 and the manual has yet to be updated.

    If the window above the vent can open, I wouldn't vent it that way. While the likelihood of you burning the appliance with the window open is rare, it could happen (burnt dinner) and you'd be sucking the exhaust into your home.
  5. R&D Guy

    R&D Guy New Member

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    Oh wait, I looked it up in the standard. Here's what page 122 of ANSI Z21.88 2005 describes for vertical clearance from a window that can be opened:

    US Requirements:
    "6 inches (15 cm) for appliances ≤10,000 Btuh (3 kW), 9 inches (23 cm) for appliances > 10,000 Btuh (3 kW) and ≤ 50,000 Btuh (15 kW), 12 inches (30 cm) for appliances > 50,000 Btuh (15 kW)"

    If I'm reading this correctly it's the same for windows that can not be opened.
  6. UncleLongHair

    UncleLongHair New Member

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    If you look at this picture from the Jotul web page:

    http://www.jotul.com/FileArchive/Photos/Gas Stoves/Jøtul GF 100/Int/GF100_BF_int_04.jpg

    This is exactly the kind of situation I have with the stove under a window (though that might just be a mock-up).

    According to the manual for that model, the center of the flue is at 16 3/4" and the flue is 6 5/8" x 4" which I assumes a maximum diameter of 6 5/8", which would make the top of the flue 20 1/16" off the floor. Assuming 9" of clearance to the windows, it fits below the windows 30" above the floor with a few inches to spare.

    But I am not sure about the cap on the outside of the wall. Is 9" required between that and the window too?

    The pictures of the caps in the manual show that the caps aren't any taller than the stove itself, which is about 22". So that would not make it under a window 30" off the floor, but what is the requirement?

    Uncle
  7. UncleLongHair

    UncleLongHair New Member

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  8. R&D Guy

    R&D Guy New Member

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    Uncle,

    Yes the outer diameter of the pipe is 6-5/8". That's a standard size pipe used in the industry. The 9" is from the top of the horizontal termination cap. Looking at the second link you provided, I clicked on the right image under "Technical Data for Jotul...." it looks like the total height from the floor to the cap is 469+.5(410)=674mm's ~ 26.5". So 26.5"+9" clearance =35.5"

    I skimmed through the Jotul install manual, and didn't see anything that showed exactly how close you could terminate under a window so I'd have to refer to ANSI Z21.88 - the US standard it was certified to.

    I attached a diagram from page 122 of ANSI Z21.88 2005, and as you can see they show the dimension taken from the top of the cap [V].

    I could be wrong, but this is how I interpret it. You may want to call the Jotul customer service line and ask for a specific dimension.



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