Severe Over Draw problems in high winds

[OffGrid]

We live in a high wind area in the Rockies. Commonly get winds in excess of 80mph in the winter up here @9600ft. Having a overdraw problem with our woodstove with winds above 40mph. Draw is not a problem even in zero winds.
Have a Scan Anderson 10, about 27 feet of ICC double wall pipe, and a ICC wind/rain cap. Burning oak, the fire will last about 5-6hrs, on windy days maybe an hour. If the door on the stove is open 6-8 inches the the draw will slam it shut. The dealer I bought the stuff from has never seen my problem. He's no help.

I've added a inline danper about 4ft above the stove, little improvement, even with damper closed, still allows some air to go thru, not technically closed.
I contacted a dealer in Laramie, Wyoming thinking they have to deal with similiar problems with high winds. He suggested a Monsoon cap from a guy from Washington state. Tried two different versions, no change.

Our prevailing wind is from the west. I know this wasn't the best solution, I attached a piece of sheet metal on the west side of the cap blocking off the wind from the west. That helped except for when the wind came from the east.

One of my neighbors has a Vacstack cap, and he put a barametric damper on a tee a few feet above his stove, the open end of the tee is open to the room drawing air from the room up the chimney. I see a couple flaws, aggresively drawing warm air from the room, and the potential of feeding a chimney fire with lots of air.

I'm considering adding one or maybe two more inline dampers and possibly a rotating cap?

Any ideas?

Thanks, Kevin

 

[begreen]

I've added a inline danper about 4ft above the stove, little improvement, even with damper closed, still allows some air to go thru, not technically closed.
I contacted a dealer in Laramie, Wyoming thinking they have to deal with similiar problems with high winds. He suggested a Monsoon cap from a guy from Washington state. Tried two different versions, no change....

I'm considering adding one or maybe two more inline dampers and possibly a rotating cap?

Any ideas?

Thanks, Kevin

60-80 mph winds are brutal. A rotating cap was my first thought. The second thought was to downsize the pipe. As to the damper, it should let some smoke/heat/flue gases go through. That's a necessity. I don't like the idea of a second damper. What if both are closed and in the middle of the night, the winds die down to 0 mph? Seems that could be a potentially lethal scenario. I'm not a big fan of baro dampers, but this is a place where I would at least try one out.

 

[savageactor7]

I no expert in this situation but awhile back JoePipe purchased a roof cricket to protect his chimney form ice damage. And I'm thinking that a higher one would shelter your chimney and lessen the effect of the wind. But really there's not much a defense that can fully compensate against an 80mph wind. I suggest a forum search for a cricket and take a look at it to better visualize what I'm getting at. Good luck Kevin and welcome to the forum.

 

[smokinj]

Barometric Draft Regulator will help in high winds

 

[thechimneysweep]

Your solution isn't going to be a cap. The Monsoon caps you tried are designed to increase updraft during windy conditions, as are the rotating (wind-directional) caps you mention and the Vacu Stack your neighbor has. I only know of one cap that is designed to prevent excessive wind-induced updrafting, and it isn't for wood exhaust.

The first thing I'd do is install a standard rain cap: you don't want any of the caps mentioned in your post, as these can only make your problem worse.

Then, I'd install a barometric damper in the connector pipe. This will require installation of a stovepipe tee: when you buy the tee, also pick up a tee cap. In the event of a chimney fire, you can put the tee cap on, covering the snout containing the barometric damper to minimize air feed to the stack.

 

[woodconvert]

I've had some spookey experiences with overdraft as well. Talk about a helpless feeling. I don't know that it's the mother of all solutions but a regular ole' inline damper is a fix. I've put one on mine and if need be I can shut her down pronto. Even if in the totally closed position it lets "some" gasses through, it's not an airtight damper...which is ideal. I've never used a barometric damper but i've looked at them and I would think they would work as well. As for putting two inline dampers in....I don't think there's a benefit to doing that and it'd be one more control to have to fuss with. Also, I don't know much about different chimney caps but I would think a standard cap with an inline damper would give you control in all occasions...at least it does for me.

man...60-80mph is quite a huff.

 

[OffGrid]

Thanks for the replies.

60-80mph is indeed quite a huff. Last winter the anemometer recorded a peak gust of 101mph.

I'll call around and try to find a barametric damper and tee.

Kevin

 

[OffGrid]

Sawdustburner,

while traveling thru Wyoming, I see alot of "H" caps....a horizontal tee flanked by two vertical tee's.

I've called alot of dealers asking about that configuration, if it's not in their catalog, they don't know what it is.

 

[OffGrid]

Sawdustburner,

funny you mention the windmill. We been living off-grid for four years, two miles from utility power. Solar and a wind turbine power our home. Kind of have a love/hate relationship with the wind. Wind is blowing make lots of power. Wind is blowing, it sucks the heat out of our home, can't keep a decent fire going with my overdraw problem.

We often have parties when the neighboring towns loose power due to the big snows. How do you find our house? Our house is the one with the lights on.

Kevin

 

[windycity]

Wow, you're worrying me. We have similar conditions here in Livingston. The stovepipe for our wood stove just went into the house we're building last week. None of the fancy doodads mentioned here were installed. I guess we'll just have to wait and see how it goes. One of our neighbors recorded a nine minute sustained 90 mile an hour gust last winter. The gust was recorded by a company that's considering putting a wind farm on said neighbor's ranch. . .

 

[windycity]

We're planning on outside air for the stove and a heat recovery ventilator.

 

[OffGrid]

Windcity,

I install residential wind turbines, most of my potential clients whole heartly believe they live in a windy site, most don't. A nine minute sustained 90mph average is scary. Pitch a tent in those winds and you'll be crying for your mommy.

Was in Cheyenne today, stopped and talked to a woodstove dealer. He commonly installs a revolving cap an a additional damper to deal with the wind. He's going to contact one of his manufacturers to see if they'll custom make something for me (cap), I'll let you know what he suggests.

I would think a dealer in Livingston has dealt with this problem?

Kevin

 

[struggle]

I relined my chimney with an under sized liner 25' long 5.5 and it increased my draft so much that I put a dampener and am border line on install another one. While I do not have 90 mph winds it does over draft and the manual for my stove even suggests that in some situations two dampeners may be needed. Sounds like for sure you could try using two of them before going any further on this.

 

[windycity]

Our house is still under construction so we don't even have the stove yet. The pipe was installed by a reputable dealer out of Bozeman who said we should "wait and see" if we needed anything other than a standard install. With winds as extreme as ours, this seems kind of nuts to me. To answer earlier posts, there aren't any building codes in effect here in Park County. The state has codes but there's no enforcement. The house will have a combination of spray foam insulation and fiberglass batts. Since there's no code, we've pretty much had to figure out how to do this ourselves. Usually, we figure out what looks good--then we figure out what it's gonna cost, and we downgrade to this next best thing.

 

[smokinj]

baromtric allows air to feed possible chimney fire also.
i think if u had damper mounted in short piece of pipe, u could bolt a metal plate so to block damper holes.damper has to be inside pipe before plate can be added. if concerned about accidentally closing damper too much, a screw in the pipe could act as a stop.
hang/tape a piece or strip of toilet paper in door opening [leave door open] of cold stove & u can get an idea of how the draft is affected during high winds & how dampeer may work. CO detectors are handy & if stove drafts inadequately, u can definitely smell smoke in the house.

what kind of problems will you have with the baromtric Draft Regulator

 

[Stihl025]

Windcity,

I install residential wind turbines, most of my potential clients whole heartly believe they live in a windy site, most don't. A nine minute sustained 90mph average is scary. Pitch a tent in those winds and you'll be crying for your mommy.

Was in Cheyenne today, stopped and talked to a woodstove dealer. He commonly installs a revolving cap an a additional damper to deal with the wind. He's going to contact one of his manufacturers to see if they'll custom make something for me (cap), I'll let you know what he suggests.

Kevin

Tell them to custom build one with a wind vane on top to turn the cap with the wind. Now there's an idea LOL