less than ideal draft solution for small jotul?

[dvellone]

my jotul nordic 100 just hasn't performed like a good wood stove should and I'm thinking it's my chimney configuration. Before I go to a drastic measure I need weighing in. I installed the metalbestos insulated (6") pipe on the outside of my house to facilitate easy and clean sweeping. I exited from the rear of the stove rather than the top and after an immedate 45 the pipe runs out through the wall to the t and then up (the stove is in a corner). The total horizontal is about three feet. Jotul says no more than three but I'm thinking that I should have run straight up from the top exit of the stove and through the house. I've seen plenty installations where the stove exits outside to the chimney and the stoves all draft well but the horizontal runs are less and they all exit first vertically for a few feet before the horizontal run out through the wall. I first thought it was just the pipe being out doors and considered building a chase to keep a warm space around the pipe but even on high pressure days when the outside temperature is in the 40's or so the stove still is sluggish and doesn't want to completely burn the wood when it's air is turned down low. I'm thinking that all that work to build a chase might be for nothing and I'd be better off running straight up through the house but I dread finding out after the fact that this isn't the solution. My firewood is seasoned well and dry, the total vertical run is 21 feet and at least three feet higher at the cap than anything within 10 feet, I'm surrounded by trees on three sides and the closest (crowns) are about 35 feet away. Any ideas?? Thanks!!

 

[Roospike]

Here is some reading to get you started before some of the replys start coming in. First question. Are you saying that you have an outside class A stainless steel chimney and your chimney is not boxed in ? (broken link removed to http://www.woodheat.org/chimneys/trichim.htm) & (broken link removed to http://www.woodheat.org/chimneys/chimneys.htm) & (broken link removed to http://www.woodheat.org/chimneys/evilchim.htm)

 

[elkimmeg]

how big is the room the stove is in? IT may not be a draft issue but a combustion air vollume defeciency or other applainces competing for the available air. like a furnace clothes dryer possibly a return air vent.
Another problem is the imediate 45 elbow. Before the draft can gain any momentum, it has to change direction and this increases
draft friction.

Are we talking about a season of non preformance or a new install? Really a decent temp differencial is needed between inside and out side. Many will poorly when temps only drop to 45 degrees. Onec it get into the 30's and colder stoves will draft better
Again you may need better practice of building a fire and establishing a good bed of coals. You could be reducing inlet air down too soon or dampering down too soon

We need more info th advise and figure out what is going on with your stove and chimney setup and opperating proceedures

 

[MountainStoveGuy]

I agree elk, it might be a pressure problem or:
Downslope on the horizontal, If i had three feet and a 45* i would have one heck of a rise in that pipe. Thats probably the biggest problem besides the possiblilty of pressure
Draft damper dislodged and stuck cosed
Chimney cap pluged after initial break in fire.
You could at some pont had a overdraft with a 21 foot chimney and sucked the insulation blanket up a bit
Thats all i can think of this early, even with the rear exit and a 45 you should get sufficient draft on a 21 foot chimney, its very very very important to have that rise.

 

[precaud]

The Nordic is a pretty, sedate stove that doesn't have a whole lot going on under the hood, but it does perform much better when vented from the top.

 

[dvellone]

Thanks for the replies. Here's more info on my setup. I'm using a selkirk metalbestos stainless double wall insulated chimney and it's entire 21 foot rise is outside. My room size is 16 x 22 and it's drafty. There is a stairwell to the 2nd floor in the room. No competeing appliances. The horizontal run has the required upslope. I used the stove all last winter and spring and having heated for many years with airtights I was disappointed with the "babysitting" I had to do to get it to burn slowly. Another curious thing is that shortly after the stove has entirely cooled the draft always reverses. When I reverse it back to normal the small piece of burning newspaper roars into the pipe and up the chimney. But I can't turn the air adjustment all the way down when I have a good fire going - the fire will smolder and go out. With the air opened all the way it burns like it should maybe halfway open. In other words, not that I want to but you couldn't overfire this stove if you wanted with the door closed. Obviously the ideal is to have the pipe entirely indoors - on the sub-zero nights once the fire dies down a bit the pipe can't stay hot enough and the draft chokes. This is my first tiny woodstove and I'm realizing how little volume of heat they send up the stovepipe. With the strong draft in the chimney I can't help thinking that this stove has to exit upwards to perform optimally and the pipe has to be in the house. But I'm reluctant to tear it all out and do it over if it's not going to help. Thanks for all the help!!

 

[MountainStoveGuy]

have you checked the cap for creosote buildup?

 

[dvellone]

The cap is clean. I keep the whole pipe cleaned real well because even the slightest accumulation cuts the draft in the stave way down.

 

[Robbie]

I honestly don't know, but that last post you made, " I can’t turn the air adjustment all the way down when I have a good fire going - the fire will smolder and go out. With the air opened all the way it burns like it should maybe halfway open."

Makes it sound like your room is too tight, maybe you could try to open a window and see if that helps, if it does, you might need an outside air supply installed.

Robbie

 

[MountainStoveGuy]

something is not adding up.
dry wood, tall chimney, breezy house, clean pipe, clean cap = hot stove. were missing something. I can tell you that little stove can crank the heat. Now you mentioned the other air tights you had, this is not a air tight, nor is it opperated like one.
i will have to think about this one.

 

[Robbie]

Another thing MountainStoveguy, having a newspaper fly up a chimney is sure not a sluggish draft I don't think, wonder if his damper is wrong ?

"But I can’t turn the air adjustment all the way down when I have a good fire going - the fire will smolder and go out."

Oxygen in room or damper adjustment maybe ?


Robbie

 

[MountainStoveGuy]

or he is using it wrong, or thinks his wood is dry when its not. there is something. hell the ceramic blanket could be lodged in there, the paper test woundnt show that because its in the stove and not the T . I have had a nordic, i know how it works on a strong flue. My first bet is wood. thats a easy test, go to safeway and buy a bundle of kiln dried.

 

[Robbie]

With that much pipe, looks like to me it would draw like crazy. He could do a good test by leaving the door cracked a little and see if that makes any difference, sure does to mine when it's a little sluggish starting out.

Would that prove anything ?


Robbie

 

[dvellone]

Where is the ceramic blanket? I cut and stacked my firewood last fall - in the woodshed nice and dry, all hard maple and yellow birch. You said you have had a nordic (Mountianstoveguy) Was it vented from the top straight up into an indoor chimney? I just keep thinking that with all factors adding up to a good fire that its the rear exit and 3 foot horizontal run that is slowing things down. I would think that I could turn the damper down all the way and with a 21 foot chimney it would burn almost too fast instead of die out.

 

[dvellone]

With the door cracked a little bit the stove roars to life. I have to say though that on the coldest nights - near or below zero - it just yawns - outdoor chimney

 

[MountainStoveGuy]

that therory doesnt hold up once the chimney is warm. You will actully get stronger draft with larger temperture differantials between the inside and outside of the pipe. Much like a hot air ballon rises much faster in cold air. The hard part is getting it warm, but once you do.... watch out!

 

[dvellone]

Does it seem crazy to take the whole chimney down and move it inside so I vent straight up from the stove? I know things can't be worse but should it work equally well the way I have it configured now with the rear exit to the 45 and three foot horizontal run ?

 

[dvellone]

I guess I'm referring to shutting the damper down to burn slowly for a few hours. It's not burning so hot and the stovepipe isn't getting too much heat so when it's that cold I have to keep it burning hot all the time for decent draft.

 

[DonCT]

Do you have a picture of your setup?

I agree with MSG, something isn't adding up. Maybe Robbie was on to something regarding the damper. Just thinking out loud.

 

[dvellone]

i can post a picture of the setup tomorrow am.

 

[begreen]

Is this a butterfly style pipe damper? If not correctly installed perhaps the handle is rotating, but the damper in the pipe is not?