Draft Problem

[fire and ice]

This goes along with slofr8 draft problems. I have a forced hot air outside wood stove. I'm having draft problems first I had to much air so I installed a manual draft. I live in town so the air conditions can change rapidly, sometimes I have to much air other times I don't have enough(with the draft closed). I want to install a barometric damper to compensate for these draft conditions and remove the manual damper. I was wondering:
1) if this can and should be done
2) will it solve my problem
3) being outside will wind cause a problem(will I need to build a box to isolate it)
4) can the straight cold air from the outside be used or will I need to build a box down to the top of the stove(top of the
stove is usually room temp.

 

[Corie]

The only thing that concerns me about using a baro outside is the force of wind against the flapper.


I love barometric dampers for almost everything, but I'm not sure about this application. If you could completely shield it from the wind so that gusts would have no effect on the flap, I think you'd be ok. It's just that the relatively light weight flapper door takes very very slight changes in pressure to swing. Often the wind blowing outside the house on the chimney is enough to suck the damper wide open for a split second. Gusty winds could have it rocking both and forth constantly and I don't think that would help the operation of the furnace at all.

 

[keyman512us]

Tell us more...A few pictures would help. You have too much draft? Sometimes not enough? Where is your setup? What part of the country? Might have a few ideas to help you.

 

[thechimneysweep]

Two things I noticed in your photos: you appear to be using single-wall connector pipe outside in the cold, and your exhaust has to travel quite a distance horizontally before it enters the chimney. This setup will not promote optimum draft.

You might consider eliminating the single-wall pipe and the horizontal run. You could come out of the chimney tee with a 30 degree chimney elbow, a length of chimney, then another 30 degree elbow and flue extender at the bottom to plug into your stove. Chimney pipe can't be cut to length, so you might have to adjust the height and location of the firebox to make your new system fit.

 

[Michael6268]

OMG A real live "Lil House Wood Stove" owner! Tell us more!

 

[Corie]

Yeah I'll agree with Tom that the single wall pipe and all those 90 degree bends are not helping. Try to get the class A down to the appliance.

 

[laynes69]

I'll agree with Corie. Barometric dampers are sensative with draft. Just the slightest wind would open it up. One other thing is if its 20 degrees outside, I don't know what that cold air would do for the draft and the chimney. Ice cold air and hot air? Is there a way to control the draft from the furnace itself, and leave the damper open in the chimney. I have a baro and love it, but I don't know what would happen being outside. I'd hate to have a chimney fire.

 

[elkimmeg]

I'm not a fan of advising unpermitted illegal installations, but not mentioned here is when you pipe was cleanned. I willing to bet single wall connector pipe exposed to extreeme cold must be a cresote factory burning less than dry seasoned wood addes to the situation . I would not be suprised if your connector pipe area requires cleanning once a week. Then again single wall connector has no right being used outside. the other part is no rise in that horizonatl portion and 180 degrees of a smoke path resistance

 

[webbie]

Hey, I see the desk there -

Is that where you "log on".....
Where the heck is that comic we had?

 

[keyman512us]

Elk:

I’m not a fan of advising unpermitted illegal installations, but not mentioned here is when you pipe was cleanned. I willing to bet single wall connector pipe exposed to extreeme cold must be a cresote factory burning less than dry seasoned wood addes to the situation . I would not be suprised if your connector pipe area requires cleanning once a week. Then again single wall connector has no right being used outside. the other part is no rise in that horizonatl portion and 180 degrees of a smoke path resistance

LOL...Elk not everbody lives in the "Peoples republic of Massachusetts"...ease up. I know you are going to shout "fire and brimstone" at me for saying so...and I know NFPA 211...etc. etc... but let's not scare this guy away!
These set-ups while somewhat crude interest me...I know the ideal way is to have the stove inside, with an interior chimeny etc., etc... But this isn't always an option for everybody.

(Elk...just 'zinging' ya buddy)

 

[elkimmeg]

Key man I did offer what I thought is the problem or contributes to his problems. I still took the time to try o to offer a solution. I made a point that had not been brought up before

I could have done it without preferencing my opinions about legality. I could have ignored it as well. Part of me pointing it out, is hopefully a reminder that, that setup presents a safety issue if cresote builds up and ingites

 

[webbie]

It does look like the install may have some other issues - as Elk seems to be holding himself back!

One that I can think of is that the ductwork from most wood fired furnaces cannot touch combustibles for a LONG way - I think most wood furnaces call for 6" from the plenum for the first "X" feet (6?) and then 2" afterwards. This is because the duct work for such furnaces can get vastly hotter than with an oil or gas unit.

Then again, that wasn't the question - but no harm in pointing it out.

That chimney is very tall and should be drafting well. I think the opinions given (insulated pipe and sloping) would go a long way toward solving the problem.

 

[begreen]

Pretty amazing. I just went over the installation instructions for this stove. There is absolutely nothing in the instructions about clearance from combustibles for the supply duct. Nada! All they recommend is that if you cut into the wall, try to run it between the 2 x 4s. However, in 'Things to Know' tips they advise: "Don’t let curtains or anything combustible be hanging in front of the heat duct."

It sounds like they are relying on the supply duct insulation for combustibles clearance protection. Hmmmm, best to keep the mice out of there in the summer. I would advise a sleeve that maintains 2" clearance from combustibles for the supply entry to the house. This would be simple and cost effective.

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