Barometric Damper needed?

[SIERRADMAX]

I'm fighting a terrible downdraft from my exterior 3 flue chimney. I'm getting smoke down the cold wood boiler flue from a woodstove on the floor above. Smoke is exhausting through the barometric damper. I've covered with a trashbag and temporarily sealed with tape. Am I better off removing the barometric and placing a cap? Not sure on performance with or without.

 

[maple1]

Do you mean the smoke is coming out one chimney, and going down another?

That just doesn't sound right to me.

How tight is your house? Where does the combustion air for the stove come from?

 

[taxidermist]

I'm fighting a terrible downdraft from my exterior 3 flue chimney. I'm getting smoke down the cold wood boiler flue from a woodstove on the floor above. Smoke is exhausting through the barometric damper. I've covered with a trashbag and temporarily sealed with tape. Am I better off removing the barometric and placing a cap? Not sure on performance with or without.

why are you using both burners? I would not remove your damper it keeps your boiler tuned all thru the burn.

My video shows why

 

[SIERRADMAX]

Current wood boiler install is in progress. My house has a three flue chimney on the exterior and is 30'+ tall. I know this isn't desireable but it's what I have. One flue serves a woodstove on the main floor, a second serves an oil boiler and the third flue is used for the Econoburn (not in operation); both in a full basement. I don't intend on operating a woodstove & the econobrun at the same time. But, after I installed the flue pipe to the Econoburn (including a barometric) and I had a fire going in the woodstove, the smoke downdrafted into the cold flue serving the econoburn and exited the barometric. For the time being, I would still like to use the woodstove, so I covered the barometric and have not had another smokey basement episode.

When I finally get the econoburn up and running, I wouldstill like to use the woodstove from time to time. If so, II'm stuck with the same problem.

 

[maple1]

That just seems really odd - to me at least. That's why I was asking how tight the house is & where the stove draws combustion air from. There would need to be pretty sustantial draw down that chimeny for it to suck smoke down - any chance it's the stove pulling it down getting it's combustion air? Did you try cracking a window to see if that did anything?

EDIT: Can you extend the stove chimney exit up a bit?

 

[velvetfoot]

That happens to me, only a smokey odor comes down the mostly unused oil flue.
Once the wood boiler is running, the draft will get going in the right direction.
Of course, then it'll come down the oil flue.
I have a Field Controls oil flue damper, that closes the flue when the oil boiler is not in use, but it still leaks some around it.
I think I'd have to mess the chimney heights, which I'm not crazy about.

 

[BoilerMan]

I'm not a fan of barametric dampers on wood apliances. Mostly for this reason, cold flue and boiler startup, you will get some smoke out the baro until the flue warms enough to draw. In the boiler room, you'll read of many of us who have to silicone and seal the smoke pipe due to smoke leakage during a cold startup, myself included. It's my theory that ha higher draft from the flue means less fan speed to maintain good secondary, why let the flue suck more air out of the house when it could be sucking the woodgas into the lower chamber? The chimney cap or lack thereof will have a great effect on draft and the wind's influence on it.

TS

 

[SIERRADMAX]

I think some of my problem is the chimney cap itself. I have one cap covering all three flues. I was thinking of adding "baffles" between each exiting flue to reduce the chance of "crossdrafting"??

Never thought of smoke exiting the oil flue. I've never had that problem with the woodstove operating... Assuming the occasional fire of the oil boiler keeps the flue warm enough. However, when the wood boiler is operating, I could develope that problem. Might have to look at an oil flue damper.

Do they make 120v oil flue dampers?

 

[velvetfoot]

http://www.fieldcontrols.com/ovd.php
I'm not saying that will cure it. It didn't cure my situation, but it must've helped.

 

[maple1]

I never get smoke out my barometric damper, or out my untaped pipe seams, at any time. Keeps the draft right at spec all the time. Without a barometric damper, wind can sometimes suck the fire right out of the fire box right up the chimney - and start a flue fire if there's creosote in your chimney. Likely less of a concern with a gasifier than something conventional, but most of these things do have draft specs. If one is in a lower or sheltered area that is less susceptible to wind gusts on your chimney top, a baro likely won't make that much difference. I'm on a windy hilltop.

 

[taxidermist]

I never get smoke out of mine either. On a windy day mine would over draft and pull the heat right past my HX tubes and i would not get good heat transfer and i would see increased flue temps.

Rob

 

[SIERRADMAX]

General consensus indicates the barometric damper is needed. For not only draft control but also I've read helps with wood consumption. Even Econoburn's manual indicates the use of a barometric damper. However, I feel I'll still have the problem with back drafting throughthe barometric. Easiest solution is to cap the barometric when the boiler is not in use.

 

[taxidermist]

General consensus indicates the barometric damper is needed. For not only draft control but also I've read helps with wood consumption. Even Econoburn's manual indicates the use of a barometric damper. However, I feel I'll still have the problem with back drafting throughthe barometric. Easiest solution is to cap the barometric when the boiler is not in use.

Yeah you will find when you quit using the wood burner and only use the EB then you will be ok. I would still fix the cap issue.
Rob

 

[goosegunner]

A member named Piker that used to sell Econoburn Had some posts about eliminating the Barometric damper to reduce puffing. He talked about using a bolt in the fan damper to weight it somehow. You could search and try to find it.

I monitor my draft at all times and the damper keeps it where it needs to be. I am not sure what the draft would hit if the damper was not there.

gg

 

[SIERRADMAX]

Now, onto location....I've seen best location is upstream of the boiler. Unfortunately, my stovepipe diesn't exit and go vertical. I've tied into a thimble about a foot higher in elevation and about 3' away from the boiler. I've installed an 8" "T", pitching slightly (1/4" per foot) towards the thimble. On one end is the 8" pipe to the thimble. On the other, is a 8"x7" reducer and a 7" barometric damper.

Will I be better off getting the damper lower to reduce the risk of back-puffing?

 

[mikefrommaine]

Now, onto location....I've seen best location is upstream of the boiler. Unfortunately, my stovepipe diesn't exit and go vertical. I've tied into a thimble about a foot higher in elevation and about 3' away from the boiler. I've installed an 8" "T", pitching slightly (1/4" per foot) towards the thimble. On one end is the 8" pipe to the thimble. On the other, is a 8"x7" reducer and a 7" barometric damper.

Will I be better off getting the damper lower to reduce the risk of back-puffing?

Looks like you might want to rotate that circulator 90 degrees. So the motor shaft is horizontal.

 

[SIERRADMAX]

Noted. Thanks

 

[Tinder]

Will I be better off getting the damper lower to reduce the risk of back-puffing?

Definitely! IMO that's a huge part of your problem.

 

[maple1]

If the white thing on the end of the T is a barometric damper, I like that spot. It is out of the natural smoke stream, and it makes a good cleanout - you could just stick an ash scraper tool in there & drag out any ash that accumulates in the horizontal pipe without taking anything apart, and even get some out of the back of the boiler if your cleaning tool is bendy or can go around corners a bit.

So is the layout in that pic the same layout that has smoke coming out of the damper?

 

[taxidermist]

I could only install mine low because it was a after thought. I am glad I did it wotks great.

Rob

 

[SIERRADMAX]

So is the layout in that pic the same layout that has smoke coming out of the damper?

Yes, Smoke is still coming out of the damper in that location.

 

[maple1]

That still seems odd to me, but others have said they've seen the same thing, so there ya go.

I'm doubtful though that putting it lower will improve that situation though - if the smoke is coming down that far, it'll likely come down lower too.

Did you try, when the smoke was coming out, temporarily opening a window just to see if that helped?

 

[taxidermist]

That still seems odd to me, but others have said they've seen the same thing, so there ya go.

I'm doubtful though that putting it lower will improve that situation though - if the smoke is coming down that far, it'll likely come down lower too.

Did you try, when the smoke was coming out, temporarily opening a window just to see if that helped?

yeah the only thing that will make the smoke quit coming down is to light the EB and shut off the wood stove. lol

 

[goosegunner]

Your wood stove is probably using the boiler flue to draw make up air into the house.

I added a 8" kitchen strainer over my barometric damper. I had a few puffs the produced embers out of my damper. It is an extra precaution that I would recommend.

gg