# Barometric Damper for Wood Stove- Correct me if I'm wrong



## RegencyNS (Feb 24, 2009)

I'm looking at a 6" barometric damper to be installed in the stove pipe directly above my Regency F2400M stove.  The reason for installing is to provide better control of the fire for longer burn times (during the night etc.).  Correct me if I'm wrong; but what I am thinking is that, after getting the fire going intially, I would be able to leave the primary air control open farther, and allow the damper to control the fire by slowing the draft.  Then after the fire starts dying down, the damper would begin to close, but with the air control open, the fire would continue to create good heat.  Basically increasing the useful heat from the stove.


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## karri0n (Feb 24, 2009)

A barometric damper should never be installed on a wood stove. It will allow cool air into the flue, both slowing flue gases and increasing the likelihood of the smoke condensing and forming creosote. A barometric damper will also cause very rapid feeding of a chimney fire if one were to start.


What is your chimney setup? There are several other solutions if you are truly experiencing an over draft situation, including a manual pipe damper. If you have less than 20 feet of pipe/liner coming off the stove, it's not very likely that you will need to install a damper.


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## EddyKilowatt (Feb 24, 2009)

Good idea in principle... anything that helps to stabilize the burn rate of our stoves would be welcome; they're fundamentally unstable in the sense that the hotter the fire, the more the draft... and the more the draft, the hotter the fire, and around and around it goes.

I think the experts here will chime in and say that barometric dampers are discouraged and/or plain old not allowed on wood stoves (and solid fuel burners in general?).    Anything that cools the flue promotes creosote formation.  Plus wood stove exhaust is dirty/sooty enough that it is hard to trust anything as delicate and easily-fouled as a baro damper... even if it is supposed to just be admitting clean air.

To me, the *upstream* side of the airflow path is the place to look to stabilize wood stove burn rates... that is, before the fire, on the draft control side.  There has long been a subset of stove models available with simple bimetal thermostatic control of draft air, and most of them are reported to work quite well (though also a bit on the delicate/easily broken side).  Thermostatic air control complicates EPA testing and probably makes compliance more difficult... but there are stoves on the market that do it, and it would be nice to see more (it is definitely on my Wish List for my next stove purchase).

Just my two cents, now let's see what the experts say.

Eddy


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## RegencyNS (Feb 24, 2009)

EddyKilowatt said:
			
		

> Good idea in principle... anything that helps to stabilize the burn rate of our stoves would be welcome; they're fundamentally unstable in the sense that the hotter the fire, the more the draft... and the more the draft, the hotter the fire, and around and around it goes.
> 
> I think the experts here will chime in and say that barometric dampers are discouraged and/or plain old not allowed on wood stoves (and solid fuel burners in general?).    Anything that cools the flue promotes creosote formation.  Plus wood stove exhaust is dirty/sooty enough that it is hard to trust anything as delicate and easily-fouled as a baro damper... even if it is supposed to just be admitting clean air.
> 
> ...



My assumption would be that the barometric damper being variable, would be able to keep the fire at a constant temperature.  Even if the air control was wide open, the stove wuld always have enough air, and the damper would variably control the fire.

Eddy, my sentiments exactly. An upstream device to better control the fire would be better.  But I can't find any aftermarket bimetallic thermostatic control that you could retrofit to an existing stove.  The only stove I have seen with something similar is the ebt on the PE Summit's.  *What other stoves do you know of that come with simple bimetal thermostatic control of draft air?*


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## RegencyNS (Feb 24, 2009)

karri0n said:
			
		

> A barometric damper should never be installed on a wood stove. It will allow cool air into the flue, both slowing flue gases and increasing the likelihood of the smoke condensing and forming creosote. A barometric damper will also cause very rapid feeding of a chimney fire if one were to start.
> 
> 
> What is your chimney setup? There are several other solutions if you are truly experiencing an over draft situation, including a manual pipe damper. If you have less than 20 feet of pipe/liner coming off the stove, it's not very likely that you will need to install a damper.



karriON, the instruction manual that shipped with my wood stove, mentions that a damper can be used with the stove for occasions of over draft.  I am just looking at it for a different reason.


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## karri0n (Feb 24, 2009)

They would be referring to a manual pipe damper rather than a barometric damper. If you are attempting to extend burn time, a manual fluedamper is likely your best option, thought if you don't have excess draft this may cause issue by slowing the draft considerably, leading to poor operation of the stove. A barometric damper, however, is against code when installed on any solid fuel device as far as I know.


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## Techstuf (Feb 24, 2009)

I've used a barometric damper for years on my woodstove.  Love it.  I burn seasoned wood and have had no issues with flammable creosote.  Helps keep flue temps down, yet in my case, not too low.  Also, the dry air helps keep any creosote build up in my case, from being wet enough to burn.  Whevever I clean my chimney, I can hold a torch to the dry crumbles of creosote removed and they won't catch.  For those with long flue runs that are wise enough to burn decent quality wood, I highly recommend it.  Barometric dampers definitely have their place in wood burning....even if that place is relatively tiny.

My wood burning efficiency jumped considerably after installing mine.  Though, admittedly, mine is a unique case.


TS


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## RegencyNS (Feb 24, 2009)

Techstuf said:
			
		

> I've used a barometric damper for years on my woodstove.  Love it.  I burn seasoned wood and have had no issues with flammable creosote.  Helps keep flue temps down, yet in my case, not too low.  Also, the dry air helps keep any creosote build up in my case, from being wet enough to burn.  Whevever I clean my chimney, I can hold a torch to the dry crumbles of creosote removed and they won't catch.  For those with long flue runs that are wise enough to burn decent quality wood, I highly recommend it.  Barometric dampers definitely have their place in wood burning....even if that place is relatively tiny.
> 
> My wood burning efficiency jumped considerably after installing mine.  Though, admittedly, mine is a unique case.
> 
> ...



Techstuf,  What type of stove is it your using?  How do you use the damper and the air control together?


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## CrappieKeith (Feb 24, 2009)

karri0n said:
			
		

> They would be referring to a manual pipe damper rather than a barometric damper. If you are attempting to extend burn time, a manual fluedamper is likely your best option, thought if you don't have excess draft this may cause issue by slowing the draft considerably, leading to poor operation of the stove. A barometric damper, however, is against code when installed on any solid fuel device as far as I know.



That is incorrect.
Yukon furnaces are UL listed to have a barometric draft regulator. I know of several others that use them too.
CharMaster,WoodChuck,FireChief just to name a few.
I will point out these are furnaces ...not stoves.

NFPA code says to follow the manfactures directions. Please be carefull extending your version of truth
 when we are talking about someones safety.

As to fires in the flue.
All wood burners can create creosote.A barometric damper should be set with a manometer so the
 proper stack temp is achieved.400-500 degrees is a good drafting chimney and at these temps it impossible 
to have much build up unless you smolder wood by restricking too much air flow ie...draft through the furnace .
Not allowing enough make up air into the home is another cause and wet wood could be another cause.
Last a flue that runs up the exterior of the home will be a cold flue and prone to excessive buildup.

There are many benefits to burning wood ,but with that comes responsibility of operation and maintaining your appliance.
We should always follow the manufactures directions.Those that cut corners or do mods may have issues.


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## bladesx (Feb 24, 2009)

Got a hot blast wood furnace, install directions show baro damper with a manual damper 18" min. ahead of it. Set baro for 5-6 , per instructions. Dosen't seem to extend burn time but does seem to even it out some as the flue temp ahead of baro does not peak as high as with out. Unit tends to run cooler with than with out. In fact it is hard to get up to 400 on the external flue gage with 2 or 3 good sized splits of oak or hickory ( 2 + year seasoned, 6-8" across ).  Without Baro flue was pullin 8 or slightly more.( My .02 worth less inflation maybe 200 mills.)


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## stoveguy13 (Feb 24, 2009)

CrappieKeith said:
			
		

> karri0n said:
> 
> 
> 
> ...


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## CrappieKeith (Feb 24, 2009)

bladesx said:
			
		

> Got a hot blast wood furnace, install directions show baro damper with a manual damper 18" min. ahead of it. Set baro for 5-6 , per instructions. Dosen't seem to extend burn time but does seem to even it out some as the flue temp ahead of baro does not peak as high as with out. Unit tends to run cooler with than with out. In fact it is hard to get up to 400 on the external flue gage with 2 or 3 good sized splits of oak or hickory ( 2 + year seasoned, 6-8" across ).  Without Baro flue was pullin 8 or slightly more.( My .02 worth less inflation maybe 200 mills.)



Not to beat on HotBlast ,they are not really a great furnace to begin with.Not much heat exchangeability,thermal mass or a secondary burn making those extra 30-40% of the btu's available.
With a .08 draft all of your heat is exiting the flue.
A draft regulator set with a manometer should create a 400 degree flue gas temp at .03" which I've personally witnessed using a heat lazer gun shot inside the center of the flue.

Make sure you have make up oxygen coming into the room to replace what the flue is draining out of the room.
Leaky basements do not normally provide enough air.Your wood is well seasoned so that's not it.
Your most likely going to have to run it harder and put a heat a lator in the flue.
I'd 1st call the company to see what they advise.
You might be better off selling your unit and getting something capable of doing the job you have expected you HB to do which is incapable of doing.


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## CrappieKeith (Feb 24, 2009)

It may be ,but check with the manufacturer then set with a manometer if approved and make sure you have make up air.


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## Techstuf (Feb 24, 2009)

I run mine on a customized setup with about 6.25 cubic feet of useable firebox.  The BD and stove combined require an OAK in my setup in order to function properly.  I do hot burns in order to heat a large thermal mass, and the BD helps keep the flue temps where I like them.  Chimney draft with the BD is not a problem at all.  The increased burn temps make for very efficient burns, allowing me to stretch the down side of the burn cycle considerably.  Often I can let the fire burn out completely and stay out for as much as 12hrs before a relight.  The neat thing about my particular setup is that during the ignition phase, the stove is wide open and the BD stays off automatically, heating the flue quickly.  Once the firebox becomes fully involved, I can shut her down and the BD self regulates according to flue temps.

I recommend a thermocouple probe to monitor flue gas temps such that in the event you are burning green wood, or neglect to sweep the chimney, and get a chimney fire, either an alarm will sound, or all flue uptakes are made to shut down automatically.


TS


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## RegencyNS (Feb 24, 2009)

This is one type I was looking at, http://www.kschimney.com/store/product.php?pid=209


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## bladesx (Feb 24, 2009)

That baro in your link is similar to the Volzgang unit that I have at present.  I think the volz was less cost though works on same principle, adjustable weight on swinging plate to regulate.

Question to the more informed, When to measure draft with manometer (spelling?) which I do have. Check draft when unit is apx  at operating at temp or? 

I will have to try reducing rate to .03


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## Stephen in SoKY (Feb 25, 2009)

Check out Hitzer Stoves if you want a bimetallic thermostat controlled unit.  They say coal, but burn wood equally well. I'm going with a model 55 starting next year.

I'm under the impression that virtually all coal fired stoves & boilers use a BD. 

My wood furnace was basically useless until I installed a BD. In my case, it made a marginal at best unit a viable heat source.


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## Techstuf (Feb 25, 2009)

There are a number of improvements for woodstoves which run counter to generally accepted ideas.....many of them are of course, not meant for the masses as they would only prove to be dangerous.  


A little knowledge is a dangerous thing.


TS


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## CrappieKeith (Feb 26, 2009)

Techstuf said:
			
		

> There are a number of improvements for woodstoves which run counter to generally accepted ideas.....many of them are of course, not meant for the masses as they would only prove to be dangerous.
> 
> 
> A little knowledge is a dangerous thing.
> ...


Before making any mods you should 1st seek the approval of the manufacturer.
As far as Yukons are concerned...a barometric draft regulator is standard equipment and has been UL listed to be apart of the operation.


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## johnsopi (Feb 26, 2009)

Keith, I have a Big Jack. How do you set the damper with out a manometer ?, and if I set it with a manometer
would'nt the setting change as the creosote build up on the inside of the damper flap. I have to clean the barometric damper 
a few times a year because the creoste builds up fast on the damper. I'm very happy with my furance and it one of the best things
I've ever bought. Keep the whole house warm.


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## CrappieKeith (Feb 26, 2009)

You really can't unless you have a heat gun that shoots a lazer to read the stack temp inside the flue.
We have a Dwyers manometer for 58$ that you could buy.That way everytime you clean it you can reset it perfectly.

I'd ask that you make sure you have 6" of make up air coming from out side the home through a pipe to 1 foot from the floor.
Also burn well seasoned wood and build smaller fires when it's mild out.
What size flue do you have?


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## johnsopi (Feb 26, 2009)

9" flue It has the outside plus a air vent in the pellum so the is a lot of fresh air  The wood is 2-3 years c/s


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## johnsopi (Feb 26, 2009)

which model  manometer I need?


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## webbie (Feb 26, 2009)

As usual, the real answer is a bit more mysterious.

In very cold climates - or in very tight houses, the use of a barometric regulator could backfire in terms of efficiency or operation...although I have really never heard too many examples of this. We could argue the room air debate in various ways. A baro allows flue gases to exit up the flue much quicker than when, for instance, a draft control is turned down very low on a stove. Shorter residence time means MORE creosote. 

I was first clued in to the use of baros with coal stoves, where they evened out the draft in a way which improved the burn in many ways. In fact, many manufacturers required them!

Soon after that I was at a trade show speaking to the top scientists at Corning Glass Works..the folks who developed the catalytic converters for wood stoves. We were discussing problems with early models, and they made it clear that MANY of these problems had to do with the flue gases passing through the catalytic converter too quickly. They also suggested a baro as a solution and I have personally used them on a number of cat stoves....way back then. 

Gulland, one of the current wood heat experts, argues against them....mostly because he is a researcher on indoor house pressure....and also lives in a really cold climate. But certainly even he would agree that the idea chimney is one which maintains an ideal draft in a number of conditions. 

A properly installed turn damper and a smart operator may be the best solution for some.....a baro for others...and a perfectly sized, perfect height, well insulated chimney may be the perfect solution for others.


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## mike1234 (Feb 26, 2009)

Man Craig, you'd think you'd at least let us all be really hard headed and argue about our favorite flavor before you were the voice of reason!   :cheese:   I wanted to point out all the flaws in someone else's argument, no one in particular, just someone I disagreed with.



			
				Webmaster said:
			
		

> As usual, the real answer is a bit more mysterious.
> 
> In very cold climates - or in very tight houses, the use of a barometric regulator could backfire in terms of efficiency or operation...although I have really never heard too many examples of this. We could argue the room air debate in various ways. A baro allows flue gases to exit up the flue much quicker than when, for instance, a draft control is turned down very low on a stove. Shorter residence time means MORE creosote.
> 
> ...


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## Peter B. (Feb 26, 2009)

I've been rethinking this whole subject and haven't come to any conclusions of my own yet.

Without question, overdraft situations exist and have to be (or should be) dealt with... the standard remedy being the manual flue damper.

I'm using one now, but still think I'm sending more heat up the chimney than I should be.  I've considered adding a second damper a bit further up the flue from the stove... but frankly, I think they're 'inelegant' to begin with and it seems like there really ort to be a better way.

The baro damper approach has known problems/tradeoffs.  The heat reclaimer has known problems/tradeoffs.

Ideally, if an EPA stove is operated properly, there should be little or no creosote deposition except on fire startup and 'cool' reload.  At other times, pretty much throughout the burn cycle, there shouldn't be a lot.

If I had an EPA stove and a bulletproof chimney, I'd be tempted to try either of the 'frowned-on' alternatives to the manual damper.

In fact, if there was a way to condense most/all of the creosote in the black pipe immediately above the stove - and prevent (most) deposition above - I would rest easy burning HOT any time I chose to... burn out the lower pipe and go on about my bizness.

My own 'research' into aluminum heat sinks came to a dead end, but I found these images that might fire other folks' imaginations.  The heat sink idea - leaving the flue the same brushable ID, unfettered with additional creo catching surfaces - still appeals to me... but I don't have a ready way of testing the theory.

Presumably, the cooling of flue temps would help precipitate creosote and (likely ?) slow the draft itself... presumably.

Simply increasing the ID of the flue immediately above the stove might also slow the draft velocity... but the volume 'moved' (I think) would increase... and the larger pipe could not be readily brushed clean without disassembly.

Oh... just dreamin'.

Peter B.

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## CrappieKeith (Feb 26, 2009)

Cool debating with the MAN!

ok if the flue has a draft regulator in it. Would it not run slower as you are mixing cold air to the flue gases thus the flues gas temps would drop.Therefore the draft would become weaker or slower not faster?


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