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  1. Joey J

    Joey J New Member

    Joined:
    Feb 11, 2013
    Messages:
    33
    Vacu-Cap.jpg

    Anyone using this cap for an air cooled chimney? Does it help draft and down draft. Like, dislike. Comments?

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  2. Pallet Pete

    Pallet Pete Guest

    Hello Joey and welcome to the forums.

    First it is a vacu-stack and yes they stop down drafts. We have one do to excessive downdraft problems the difference is night and day. What symptoms are you having what type of stove do you have how tall is your chimney and how dry is your wood ?

    Pete
  3. Machria

    Machria Minister of Fire

    Joined:
    Nov 6, 2012
    Messages:
    1,113
    Loc:
    Brookhaven, Long Island
    I don't have that exact one, but a similar high wind/storm cap. Instead of the sheet metal going around it vertically like that one, mine has a ring of sheet metal around it horizontally. Same concept, and does the same basic thing which is create a "vacume" on the backside of the cap (downwind side), which creates a good draft in the flue instead of the wind blowing down into the flue, putting a downward pressure or neg draft in it.

    Mine works great. I have one on both my oil burner flue, and stove flue. The stove flue is new, and had it from day one so I can't compare it, however the fireplace on that flue used to back-puff smoke into the room constantly when it was windy, the stove has never done that. However, I ran my oil burner for 10 years without it, with all kinds of issues with it. Back-puffing into the burner blowing smoke into the house and blowing out the burner (the pressure into the burner was prematurely buring out sensors, transformers, electrodes.....). I change the cap to one of these, and all those problems dissapeared instantly.

    My house is on stilts and very high up, and on the water with no protection (no tree's or other buildings...) from the very strong ocean winds. So it is almost always blowing hard directly omto the house and flue. So me thinks they work awesome. They also keep more rain and snow out in bad storms. They cost pennies more than a regular cap, so I'm not sure why they are not mandatory and/or not used more often at least.
  4. Eater309

    Eater309 Member

    Joined:
    Oct 27, 2011
    Messages:
    29
    Loc:
    E. Central IL
    Joey,
    I have the same cap myself. Been burning wood for two winters with it. I still have downdraft problems when wind comes from the North direction at speeds over 10-12 MPH. I do think I need more stack though. Another thing, birds can still get down these caps. I had that problems two to three times this spring. (birds end-up in the firebox, no fire burning then) I made a wire screen out of stainless steel wire and that solved the bird problem. I don't remember for sure the cost but thought it was rather expensive. Only my 2 cents worth!
  5. Machria

    Machria Minister of Fire

    Joined:
    Nov 6, 2012
    Messages:
    1,113
    Loc:
    Brookhaven, Long Island
    Both of mine look like this one, and as you can see it came with a stainless screen on it.

    Eater, when a directional wind affects the chimney like your describing (North wind), I'm told that can ussually be corrected by makign the chimney higher, or lower. The cap is probably getting deflected winds from the building, or tree's, or other obstruction. I also had that same problem (also a North wind issue) on my oil burner chimeny. In my case, we raised in about 6' and that problem disapeared. My chimeny is on the north side of the house, and the engineer explained there was a kind of vortex created on that side of my roof with a north wind. The 6' hieght, raised it out of that "vortex".


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  6. Eater309

    Eater309 Member

    Joined:
    Oct 27, 2011
    Messages:
    29
    Loc:
    E. Central IL
    Machria,
    I am planning on raising my chimney also about 4 ft. Waiting for spring/summer. I have a really steep pitch on my house, also my chimney is on the north side of my house. It's a through the wall chimney with 2, 90 degree elbows and 1, 30 degree offset to go through my eve. It's triple wall stainless steel. I sure hope raising the chimney height will solve the problem. I have had a few burn that really smoked up the house this year. This is the first year that I have had the problems. Thanks for the advice.
  7. Machria

    Machria Minister of Fire

    Joined:
    Nov 6, 2012
    Messages:
    1,113
    Loc:
    Brookhaven, Long Island
    That's exactly what I had on my oil burner when I had problems with it. Steep roof...., 90 turn out of burner room and up side of house, then around the soffet and up. Raising it and chaning to the vacu cap eliminated all the problems. And it is running more efficiently now as well. I'd say it burns 20 to 30% less oil, so it made a huge difference.
  8. nate379

    nate379 Guest

    I have a regular cap on my chimney. Wind doesn't really effect it, maybe increasing the draft a bur. We get 60-70mph winds fairly often in the winter.

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