Any Chimney/fireplace experts out there?

Discussion in 'Random Ramblings' started by snewman, Dec 8, 2009.

  1. snewman

    snewman Songster

    Feb 22, 2007
    Belleville, WI
    I'm wondering if someone might be able to help me. I installed a fireplace this fall with a double-walled stove pipe chimney. It is the height required by code (2 feet higher than the part of the roof within 10 feet). The other day I had a terrible time with it. It was windy outside and the wind blew HUGE amounts of smoke and ash down the pipe and out into the living room. I mean, it filled the house. Every surface was covered in ash and it looked like it was snowing inside. I had a fire going at the time, and the smoke alarms went off, I had to open windows, etc. It was like the wind had a direct line straight down the chimney. I had to scoop the burning logs out of the fireplace and carry them outside because it just wouldn't stop. We don't have doors on it yet, which could help, but does anyone else have suggestions about avoiding this problem? I mean, I can't believe that I won't be able to have fires any time it's windy (like, all winter). My dad thought maybe going a little higher with the chimney pipe, but I don't know. Any thoughts are welcome!

  2. rebelcowboysnb

    rebelcowboysnb Confederate Money Farm

    You could replace the cap with a pipe elbow facing away from the wind. It is even possible to put it on loosely an add a fin so it weather-vanes away from the wind. Also where is the air leaving your house? For air to come down the chimney then it must be going back out just as fast somewhere else.
  3. thebritt

    thebritt Songster

    Mar 5, 2009
    Humboldt County
    Do you have any large trees near the house? The same thing happens at a friend's house - he has a big pine that catches the wind and swirls it right back down the stovepipe. He may have to have that tree seriously pruned or removed.
  4. redstars

    redstars Songster

    Mar 15, 2009
    south dartmouth ma
    They sell a cap that swivels with the wind to prevent that from happening.
  5. The only time we have ever had smoke come back out of the fireplace is when you just start the fire. If it's windy and the flue isn't warm and drawing good the smoke will come out. Was the fire burning well or just smoldering? Also, how "tight" is your house - the fire draws air from inside and up the chimney. If your house is semi airtight there isn't as much air for the fire. When we have a fire going you can hear the air going up the chimney.

    Steve in NC
  6. seismic wonder2

    seismic wonder2 I got mad ninja skills

    Feb 3, 2007
    san diego ca
    The code requirements are the MINIMUMS to keep the house from burning down.
    You need to raise the chimney about two to three feet.

    Many times when wind hits the house from the side, it goes straight up, creates a vortex at the roofline and swirls around and back down on top of the roof.
    Light winds aren't a problem because the swirl is small. When it picks up though the swirl can be four to five feet tall at the roofline, when the air rotates back down it goes right down your chimney.

    It's hard to explain without drawing a picture.
    Just raise the thing another two feet and that should cure your problem.

    ANOTHER problem may be your house it too weather tight.
    when smoke and heated air go up the chimney it needs to be replaced by air from the outside. (preferably from the windward side of the house)
    If your replacement air is coming from the LEEWARD side of the house, everytime the wind gusts it creates a vaccuum and sucks the smoke down the chimney into the house.

    It's all a combination of thermodynamics and fluid dynamics.
  7. I have WHAT in my yard?

    I have WHAT in my yard? Songster

    Jun 24, 2008
    Eggberg, PA
    That's why our system has an outside air draw, so the heat stays in the house!

    We have a wood burning masonry heater that DH designed. Very very cool and provides most of the heat for the house.

    He said to tell you you're chimney is not high enough (as was said before) and you've got the wrong kind of cap on it, if you have a cap at all. There are several styles which divert the air or break up the flow to prevent this.

    Oh, he added really make your chimney taller, he (his opinion mind you) thinks a chimney that short is a fire hazard.

  8. wildorchid053

    wildorchid053 Songster

    May 12, 2009
    syracuse area, ny
    if your fire is hot and still doing it.. try cracking a window open to get a good air draw it will stop if from sucking the stuff back down.
  9. snewman

    snewman Songster

    Feb 22, 2007
    Belleville, WI
    Thank you everyone! I'm so relieved to have good suggestions for my problem, and they all make perfect sense. My fireplace can be outfitted with an outside air intake system, so I'll get that done (DH will, anyway), and we can easily make the pipe taller. I'll look into the swiveling/angled caps. I had to smile at the suggestions that my house is too airtight. It's a drafty old farmhouse with good "ventiliation", I'll kindly call it. We like to think that reduces the risk of carbon monoxide poisoning [​IMG]

    Any suggestions on where to look for the swiveling and/or angled chimney caps?

    Thanks again for the help!
  10. jafo

    jafo Songster

    May 2, 2009
    From what I read here, is that you built a fireplace, and the flue is a double walled smoke pipe, correct? I take it that you neglected to install a damper in the flue??? Is it a stone fireplace, with the smokepipe buried now under a wall or sheetrock? If so, there's half your problem, (no damper) and I'd also think that there at this time is no cap of any sort on it??? You should have a cap, swivel or no swivel. Sounds to me you might be in a position too that whatever you live in and the configurations of the treescape, buildings etc, are prime to create downdrafts on the chimney. I could have been just a freak downdraft, but any real fireplace, new or old, has a damper. A cap, and a damper, coupled with fresh air intake (in this case your living space air volumn, unless you have a window opened slightly) not only controls the burn, but PREVENTS unwanted backdraft blasts, due to windy, downdraft conditions outside. Your hieght, 2' above ridge line is fine.

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