Weather vs. Draft

[international5288]

I'm sitting here tonight with a smoke smell in the house thanks to rollout when I open the stove door. (VC Winterwarm Small, 25' exterior chimney w/insulated 6" liner that is clean as a whistle, etc etc) I've had good performance with the stove all day long except tonight. It is 0 degrees outside with a baro of 30.50. 0 wind. It is 71 degrees inside but I do not know what the baro is in here. Normally I have a draft strong enough to suck small children and pets right up the pipe, but not tonight. It is not something mechanical or the wood, none of that has changed. The stove is running along at 450-500 like usual. (stovetop temp, not stack) However, not much draft and I have the air turned up 100% to get the temp.

Why? Educafy me.

I live in an old farm house that is reasonably but not completely "tight." I tried cracking open a door to see if that helped, cold air rushes in... but we can't have that for very long and stay warm now can we? I guess my only idea is that the outside baro increased so quickly this evening that the house is still de-pressurized and "catching up?" I would think that with the temp differential between a 450 degree stove and 0 degree outside would overcome an air density difference? It baffles me.

Oh I can't wait to get an outside air kit installed!

 

[rumme]

try cracking your window a slight bit ?

 

[LLigetfa]

try cracking your window a slight bit ?

Downstairs. Close the one upstairs.

 

[Martin Strand III]

Everything else being OK, I think your trouble is your exterior chimney; the chimney being an exceedingly important part of your wood stove heat system. Even with an insulated steel liner in the outside chase, at 0* F cold air gets down low in the chimney creating the back burp to the inside.

Compare your set up to one with a centralized interior chimney with warm inside 68* F (or so) air around it until it penetrates the roof to the cold outside. That's a lot more heat, even starting 'cold', to create a better draft which thrives on temperature differential between inside and outside, length in the vertical aspect, lack of offsets and free clearance outside (10-2-3 rule).

That's my take. Unfortunately for you, your set up is tough to change now. Sorry, man.

Aye,
Marty

 

[international5288]

Thanks for all the responses so far. This issue doesn't happen very often so it is more of a curiosity to me than a real problem. The only thing with the cold chimney suggestion, last week when it was -20 I still had great draft. The high temp today was 10, so it only dropped 10 degrees until the smoke rollout started. So that's why I'm leaning towards a baro change being the culprit? It was 30.00 earlier and now 30.50. I wish I knew what it was inside, to compare. Has anybody else been able to see what their baro differential is inside vs. out? Next time I have this issue I'll try opening a low window and "burping" it to see if it helps.

Thanks!

 

[international5288]

UPDATE

I am never too proud to admit a mistake! This morning I was attempting to re-start a fire and was having the same smoke rollout problems. OK, time to check things over top to bottom. I climbed the roof and immediately found the problem. Sometime late yesterday afternoon, a thin layer of creosote peeled off the underside of my chimney cap, fell into the liner in the shape of an inverted cone, and plugged it up. How on earth 1) the draft force did not pop it out, and 2) the fire kept burning nice and hot, I have no clue. The plug was the consistency of expanding foam about 1/8" thick, I poked it out and ran a brush down the liner just to be sure things were clear. I had about a half pint of creosote in the stove when I was done. I can look up and see about 75% of my liner from inside the stove, all I see is a little bit of light tan dust and the gold/blue hue of the liner. At the top it was clean except the last 1' or so, which the brush took care of. Beats the heck out of me. I ripped the screen off the cap just to see if that will help in the future.

Moral of the story is, when my grandpa warned me what happens when you ASSume things, I should have listened. In this case I assumed the liner was clear, I was wrong.

 

[Backwoods Savage]

At least this has a happy ending! lol


Marty: my stove pipe runs horizontal to the wall then out to a tee and up the side of the house. We have no problems with this setup. I know, it sounds contrary, but it works. Not only that, as you know we have a cat stove so the flue temperature is not very hot and we let the fire smolder a lot. It can be done!