Excess draft problem

[slofr8]

Hi everyone,
this is my first year in the new house and I put in a Hearthstone Heritage wood stove. I have about 12' of double wall pipe up to the ceiling and about 12' more of stainless prefab after that. Straight out of the top of the stove. No elbows. Hearthstone puts the max stove top temp. at 300-400 F. Well this is fine when out side tenps. are between 10F and 30F but lower than this and I lose control. At -10F stove top hits about 500F and the last few nights we had -15F to -20F. If I load the stove for over night burns she gets up to 600F+ with the damper shut all the way down.
As I see it, if I want to be able to control my fires at these temps. I can either install a flue damper or try to somehow restrict the air flow coming into the stove from the back. When I hold my hand over this intake hole I can really notice the fire calm down.
What would you do?
Thanks, Dan.

 

[MountainStoveGuy]

on a permant basis, i would put a damper it. If you modified the air imput, you could void the listing for the stove. Im not saying its not safe to restrict combustion air, im saying if you had a fire, then you would be in trouble.

 

[Corie]

Is installing a barometric damper absolutely against the rules for a non-cat stove like this? This seems like a perfect candidate.

 

[MountainStoveGuy]

no, i wit would be a perfect canadate. I was talking more in the line of making permanant modifications to the stove intake manafold.

 

[Corie]

Oh I know MSG, I wasn't responding to your post, I was just wondering.


I know its been say that barometrics are a perfect marriage with a cat stove, but I was wondering about the non-cat. Talk about consistent and stable results, get the baro set where you want it and never touch it again. THe overdraft problem will disappear.

 

[MountainStoveGuy]

honestly, i dont know much about them, one of my installers uses them. Do they go on the back of the stove or inline with the chimney/

 

[Corie]

Inline with the chimney. THe little flapper door has weights that adjust how much air is added to dilute the flue gases and slow down the draft. Really really sweet units. I think any situation where there is a strong draft should have one, just because it equalizes everything and helps the fire burn longer and with more consistent heat.

 

[struggle]

Slo,

I have a Mansfield and about 20 minutes ago installed a dampner 18" above the stove. I was having overdraft problems big time it seems. I could only get 4 hours burn time and if I loaded the stove to the hilt it would burn very fast.

I am on my first burn with the dampner closed just over half way after the chimney is warmed and it really seems to slow the fire down and the stove is coming up to temp faster.

At this momnet I would highly recommend a $5 dampner be installed.

I had no problem getting the Mansfield up to temp it was just a matter of keeping the temp once it got there.

 

[Corie]

The difference between the stack damper and the barometric damper is convenience. With a stack damper, whoever is loading the stove needs to know how to set it. Of course if its 45 when you leave for work and then 17 when you go home, the setting from the morning might not be quite right anymore. The simply automation of the baro damper is constantly adjusting the draft.

Not to get all preachy on the baro dampers, but they are a valuable tool for getting controlled and long burns out of a stove.

 

[begreen]

Do they make a barometric damper for double wall pipe?

 

[Corie]

The barometric part just slips into the end of a Tee, usually. If you could install a tee into the pipe off your stove, you should be able to slip the barometric right in.

 

[Michael6268]

Ive always been leary about barometric dampers with wood stoves. While they would greatly help almost any stove, I worry about a couple of things.

1-With the damper allowing cooler air from the room into the flue, excess creosote.

2-With the excess creosote increased risk of a chimney fire.

3-In the event of a chimney fire, no way to shut down the air and the baro would just fuel the fire. If you were home, I suppose you could hold it shut with a pair of tongs or pliers to shut down some of the air.

 

[Corie]

Simple fix to that problem Michael.


Clean your chimney.

 

[Michael6268]

Simple fix to that problem Michael.


Clean your chimney.

I do, twice a year. That's enough for me. But again, it has been thrown around many times and I don't think anyone has a clear answer- it does seem logical that the chimney would gunk up faster, and that in the case of a chimney fire, that it would only aid the combustion. I personally have never seen a manufacturer of a wood "stove" recommend a barometric. My coal stove, that's another beast, and a baro on a coal stove is a good thing!

 

[Corie]

You definitely raise good points michael and I certain shouldn't have posted in a manner that would discredit what you said.

Absolutely true in all respects, but from the real world experience I have using barometrics on wood stoves, I have to tell you that the creosote build up isn't much of a problem. Yes, where the cold air enters the flue gas flow, there is some expected creosote build up. Otherwise though, I don't notice serious build up to its use anywhere.

Case in point, burned a Russo C-80 this year, which is a coal only stove. However the family didn't have the money for coal, but did manage to gather a good amount of wood. They've burned about a cord so far of wood that I don't consider to be particularly well seasoned. Other than 1/4" of the dry flaky creosote at the barometric entrance, I didn't see anything out of the ordinary all the way up the stack.

If that was a modern stove, with reburn techonology I can't see the creosote build up being nearly as high.

 

[laynes69]

My wood furnace recommended one. We have one and our overdrafts have stopped. You will use more wood and get less heat if you have overdraft. One thing with the creasote, the baro slows down the air inside the firebox. When set correctly it allows a more even burn and it slows down the rate of the flames. We still get secondary combustion at almost all of the time, and it allows for more heat from the furnace or stove. I was worried about the same thing, but my flue stays much hotter and my stove produces more heat with less wood. We also get a longer burn time. Placement plays a big part. We are happy and our chimney and flue have stayed clean.