Chimney Height

ddahlgren · Post by **ddahlgren** » Sat. Jan. 25, 2014 3:49 pm

I am still fixing the Crane 404 finally lined up a friend with a portable welder to fix pins for door hinges. Running my wood stove today and crazy wind from all directions lost draft and blew out the wood fire to relight with a series of big thumps. It is only 11 feet as a single story addition. 6 ft single wall and 5 ft triple wall. I could add 3 more ft triple wall but then need supports for wind and might to start looking a bit silly. Any source for an inexpensive manometer so I can get a handle on how much or little draft I have to play with?

michaelanthony · Post by **michaelanthony** » Sat. Jan. 25, 2014 3:59 pm

It does sound like you need more height if the wind is blowing out your wood stove. Do you have trees or a higher roof line close by? Some pic's of the outside chimney would help. Check amazon for the Dwyer Mark II Manometer and Grainger as well. I believe a member has one for sale, check the classified section of the forum. I don't know if measuring the draft of a wood stove would give you the results you need for a coal appliance.

ddahlgren · Post by **ddahlgren** » Sat. Jan. 25, 2014 4:39 pm

michaelanthony wrote:It does sound like you need more height if the wind is blowing out your wood stove. Do you have trees or a higher roof line close by? Some pic's of the outside chimney would help. Check amazon for the Dwyer Mark II Manometer and Grainger as well. I believe a member has one for sale, check the classified section of the forum. I don't know if measuring the draft of a wood stove would give you the results you need for a coal appliance.

I am thinking stack temp to overcome the backdraft is the same wood or coal. With a magnetic thermometer I need 350 and with a probe 500 to get past it to where the fire slows for a second then gets back to normal so no matter what the fuel draft would be the same. I am all in on coal as the woodstove is sold and gone the minute I move it out as is all wood too to fund the coal stove and coal.

michaelanthony · Post by **michaelanthony** » Sat. Jan. 25, 2014 5:36 pm

If you are stating start up temps for you to warm the chimney I can understand, but my temps are as such: box stove after baro 120*-140* and stove is 450*, Vigilant no baro or mpd 220*- 260* 6 inches from stove breach and stove is 650* with established fires. I hope this helps.
Mike.

Berlin · Post by **Berlin** » Sat. Jan. 25, 2014 10:47 pm

stainless stack w/ little thermal mass and excessively short. That combination is sure to give you issues w/ draft. you need at least another three foot section.

McGiever · Post by **McGiever** » Sat. Jan. 25, 2014 10:53 pm

ddahlgren wrote:
michaelanthony wrote:It does sound like you need more height if the wind is blowing out your wood stove. Do you have trees or a higher roof line close by? Some pic's of the outside chimney would help. Check amazon for the Dwyer Mark II Manometer and Grainger as well. I believe a member has one for sale, check the classified section of the forum. I don't know if measuring the draft of a wood stove would give you the results you need for a coal appliance.
I am thinking stack temp to overcome the backdraft is the same wood or coal. With a magnetic thermometer I need 350 and with a probe 500 to get past it to where the fire slows for a second then gets back to normal so no matter what the fuel draft would be the same. I am all in on coal as the woodstove is sold and gone the minute I move it out as is all wood too to fund the coal stove and coal.

X2 the added height.
Have you a pipe cap...some here dislike caps...but in your case it may help.

ddahlgren · Post by **ddahlgren** » Sat. Jan. 25, 2014 11:36 pm

Yes have the Dura-vent cap that came with the kit. Only have issues when wind out of WSW and over 20 knots. There is a tree 75 feet away and tall ~60 ft tall. Current chimney meets 3-2-10 though just barely.

KLook · Post by **KLook** » Sat. Jan. 25, 2014 11:43 pm

I run a boiler SS chimney with a cap, but I have a straight shot, about 15 ft. with at least 10 of that above the roof line. Draft is never an issue and never has been. I used to run a wood boiler with this setup also.

Kevin

carlherrnstein · Post by **carlherrnstein** » Sun. Jan. 26, 2014 2:44 pm

The 3-2-10 rule, doesn't mean the chimney will draft well. That just means that there wont be a dangerous amount of embers falling on your roof.

Berlin · Post by **Berlin** » Sun. Jan. 26, 2014 3:31 pm

carlherrnstein wrote:The 3-2-10 rule, doesn't mean the chimney will draft well. That just means that there wont be a dangerous amount of embers falling on your roof.

exactly.

ddahlgren · Post by **ddahlgren** » Tue. Jan. 28, 2014 10:07 am

Chimney has not acted up since that one day, drafts just fine since then. Would a MPD have cut down the effect of the wind? My gut feeling is no it would not. I wonder if on coal it would have been less of a problem as I don't think you are going to blow the fire out with a gust of wind. I only got some smoke iin the house after the fire was out.

michaelanthony · Post by **michaelanthony** » Tue. Jan. 28, 2014 10:13 am

[quote="ddahlgren"]Chimney has not acted up since that one day, drafts just fine since then. Would a MPD have cut down the effect of the wind? My gut feeling is no it would not. I wonder if on coal it would have been less of a problem as I don't think you are going to blow the fire out with a gust of wind. I only got some smoke iin the house after the fire was out.[/quote]

In regards to a mpd making a difference, if water is sucked through a garden hose or a straw, which one would fill a 5 gallon bucket first?

Sunny Boy · Post by **Sunny Boy** » Tue. Jan. 28, 2014 10:53 am

ddahlgren wrote:Chimney has not acted up since that one day, drafts just fine since then. Would a MPD have cut down the effect of the wind? My gut feeling is no it would not. I wonder if on coal it would have been less of a problem as I don't think you are going to blow the fire out with a gust of wind. I only got some smoke iin the house after the fire was out.

No, you won't blow out a coal fire, but it may stall, or even reverse the draft some. Then you risk getting CO in the house.

With a short chimney, you may be getting higher pressures near it's top from wind-gust turbulence - when the wind is from a certain direction in relation to your roof and/or that tree.

If it happened once, the safe thing is, don't assume it can't happen again.

As the others have said, a taller chimney is better. And, adding a mano, or a baro, isn't going to make a short chimney act like a tall one.

Paul

BPatrick · Post by **BPatrick** » Fri. Jan. 31, 2014 10:13 am

Taller Chimney and make sure your cap is installed and working properly.

ddahlgren · Post by **ddahlgren** » Sat. Feb. 01, 2014 2:53 am

Sunny Boy wrote:
ddahlgren wrote:Chimney has not acted up since that one day, drafts just fine since then. Would a MPD have cut down the effect of the wind? My gut feeling is no it would not. I wonder if on coal it would have been less of a problem as I don't think you are going to blow the fire out with a gust of wind. I only got some smoke iin the house after the fire was out.
No, you won't blow out a coal fire, but it may stall, or even reverse the draft some. Then you risk getting CO in the house.

With a short chimney, you may be getting higher pressures near it's top from wind-gust turbulence - when the wind is from a certain direction in relation to your roof and/or that tree.

If it happened once, the safe thing is, don't assume it can't happen again.

As the others have said, a taller chimney is better. And, adding a mano, or a baro, isn't going to make a short chimney act like a tall one.

Paul

It is pretty hard to test for something that happens once a year as you have no idea if really fixed or it didn't happen. The landscape here has loads of issues. I am 500 ft. from the water and 60 to 80 ft. above it 200 yards further from the water there is an 80ft. cliff. The wind patterns off the water can swirl all over the place to the point it has rained up into the sidewall vent for the stove. If I add another length of Dura-vent to the stack I have to add supports and that is a trip to the historic district Nazis. It took a year to get a building permit to put up a carriage house that looks period correct.

BPatrick I am sure the cap is installed correctly but have no idea as to how to test it.