Inversion? with out side chimney.

[jatoxico]

So I got up this am to start a fire. Totally cold start since its been warm this last week. When I open the stove door I can feel the cold air rushing down. Throw 4 crumpled pc of newspaper in and shut door smoke starts pouring into the room through the secondary air and past the door gasket.

Long story short tried a hairdryer, made a mess I'm annoyed. This happens couple times a year. First question is this common, what do I do? Secondly what if this happened as I allowed a fire to burn down? could fill the house w/ smoke and CO is there a fix?

Its fully lined w/a 6" liner with roxul at the base and cap. Probably 22-24' in total. Did I mention this sucks?

 

[Excavator]

Try lighting newspaper and holding up near the stove exit while door is open. It should correct the back draft

 

[jatoxico]

Try lighting newspaper and holding up near the stove exit while door is open. It should correct the back draft

Thanks for the reply but that didn't work. I was trying to keep the post short so I left out some details. The draft (reverse) is pretty strong. Maybe I will pop the baffle out of the way and try again but right now I'm gonna sit tight. I stuck a candle in there see if I can slowly coax it along w/o producing smoke. Wonder if its a weather thing.

 

[oconnor]

Is your stove in the basement? If so, open a window. Essentially, when this happens your house has become a better chimney than the flue is. Stack effect does this. Equalizing the pressure of the stove room with the outdoors will help, especially in the basement.

 

[jatoxico]

Is your stove in the basement? If so, open a window. Essentially, when this happens your house has become a better chimney than the flue is. Stack effect does this. Equalizing the pressure of the stove room with the outdoors will help, especially in the basement.

Well not a basement but a lower level. I'll search for stack effect fixes but whats the main cause, attic issue?

 

[oconnor]

Stack effect is not as much a problem as a fact of physics. Warm air rises, and effectively you have increased pressure in upper areas and a relative decrease in lower areas.

The flue reversal you experienced is generally pressure related. Other factors could include a bathroom or kitchen exhaust fan that was on at the time. There is a link in my signature block for the Guide for Residential Wood Heading (I think that's the title) - it has a good section on flue reversal causes.

Be particularly careful if you are starting the stove cold and then leaving the house. If you draft it back too far before the flue is warmed it can reverse again. Happened to me once at bedtime, filed the whole basement with smoke. I was doing a few things wrong at the time - fans blowing air out of the room and wood wasn't dry enough.

 

[jatoxico]

Brent the link is down but I found some info elsewhere so thanks.

Excavator, I left a candle in the stove for an hour then moved the baffle out of the way and tried your idea again and I'm up and running. So we'll see if that is a reliable fix.

Still concerned that on a very cold night the draft could reverse on a coal bed and cause me issues. The other thing is its hard to tell the difference between a downdraft and a stove that's simply cold. Guess I will light a match as a test if I suspect trouble. House full of smoke at 6am was a sucky start.

 

[Newschool]

Brent the link is down but I found some info elsewhere so thanks.

Excavator, I left a candle in the stove for an hour then moved the baffle out of the way and tried your idea again and I'm up and running. So we'll see if that is a reliable fix.

Still concerned that on a very cold night the draft could reverse on a coal bed and cause me issues. The other thing is its hard to tell the difference between a downdraft and a stove that's simply cold. Guess I will light a match as a test if I suspect trouble. House full of smoke at 6am was a sucky start.

I had the same thing happen yesterday (sat) morning. First time ever. I am in PA. Wondering if the weather was just really weird.

 

[begreen]

Here is a good link on chimney function. http://www.woodheat.org/all-about-chimneys.html

Draft reversal can be caused by exhaust fans in the house, the stack effect or perhaps strong negative pressure in the basement, (boiler pulling hard for air), clothes dryer, etc.. The stack effect can happen with an open upstairs window (even just a crack), open or leaky attic vent or door, upstairs bathroom vent, or unsealed upstairs recessed can fixtures.

 

[jatoxico]

Here is a good link on chimney function. http://www.woodheat.org/all-about-chimneys.html

Draft reversal can be caused by exhaust fans in the house, the stack effect or perhaps strong negative pressure in the basement, (boiler pulling hard for air), clothes dryer, etc.. The stack effect can happen with an open upstairs window (even just a crack), open or leaky attic vent or door, upstairs bathroom vent, or unsealed upstairs recessed can fixtures.

That's my prime suspect right there BG, that and my AC return although that should be a closed system. Thanks for the link I'll read up.

 

[Lumber-Jack]

I have a theory that I believe must be correct, though I haven't been able to test it yet.
A lot of people have experienced this phenomena where they have a back draft down a cold flue that is so powerful that it pushes the smoke of a new fire back into the house. The thing is, if it was just stack effect created by the shape of the house and the cold, you would think that it would happen any time it's cold out since the shape of the house remains unchanged, all you need is cold weather and a cold chimney to initiate the effect, but the fact is it doesn't always happen with just those two circumstances. I have already confirmed that normal household exhaust vents don't have the power to create this effect. It's easy to test, simply turn all your vents on in the house when you have a cold stove and light the stove, they just don't create that effect to pull the smoke down out of a cold stove, not in my house anyway. So, there must be something else involved.

I believe this occasional strong back draft phenomena is caused by rapid change in the barometric pressure.
If your house has been sitting in a low pressure system for a while it will equalize to the low pressure outside, and when a strong high pressure system moves in rapidly it takes time for the house to adjust to the new outside pressure, and the only way that is going to happen is by air being forced into the house from every opening in the house, including the chimney flue. The greater the high pressure system, and the more rapidly it moves in, the stronger the air will flow down the flue. This is why opening the doors in the house will generally help, because it allows the pressure to equalize in the house faster and reduce the in rushing of air down the flue.
The only way I can prove if this theory is correct or not would be to have a recording barograph outside and wait until I get this phenomena of smoke billowing in the house from the cold stove when I'm trying to light it. If this only happens while I am experiencing a rapidly approaching strong high pressure system, then I'd be able to confirm this theory.
Anybody have one of those computer monitored weather stations?

 

[begreen]

Sealing upstairs leaks can make a big difference in heating and in draft-reversal in a cold chimney. You want to get the first floor to neutral or positive pressure.

 

[jatoxico]

I have a theory that I believe must be correct, though I haven't been able to test it yet.
A lot of people have experienced this phenomena where they have a back draft down a cold flue that is so powerful that it pushes the smoke of a new fire back into the house. The thing is, if it was just stack effect created by the shape of the house and the cold, you would think that it would happen any time it's cold out since the shape of the house remains unchanged, all you need is cold weather and a cold chimney to initiate the effect, but the fact is it doesn't always happen with just those two circumstances. I have already confirmed that normal household exhaust vents don't have the power to create this effect. It's easy to test, simply turn all your vents on in the house when you have a cold stove and light the stove, they just don't create that effect to pull the smoke down out of a cold stove, not in my house anyway. So, there must be something else involved.

I believe this occasional strong back draft phenomena is caused by rapid change in the barometric pressure.
If your house has been sitting in a low pressure system for a while it will equalize to the low pressure outside, and when a strong high pressure system moves in rapidly it takes time for the house to adjust to the new outside pressure, and the only way that is going to happen is by air being forced into the house from every opening in the house, including the chimney flue. The greater the high pressure system, and the more rapidly it moves in, the stronger the air will flow down the flue. This is why opening the doors in the house will generally help, because it allows the pressure to equalize in the house faster and reduce the in rushing of air down the flue.
The only way I can prove if this theory is correct or not would be to have a recording barograph outside and wait until I get this phenomena of smoke billowing in the house from the cold stove when I'm trying to light it. If this only happens while I am experiencing a rapidly approaching strong high pressure system, then I'd be able to confirm this theory.
Anybody have one of those computer monitored weather stations?

I agree the weather is a component. We have a storm coming into the area so I guess we are at lower pressure with a high moving in.

 

[begreen]

Long Island is not in a serious low pressure area right now. Falling pressure may exacerbate the situation but I don't think this is the core issue

 

[weatherguy]

The pressure was probably falling when the OP was having this problem, not to say what Lumber Jack said couldn't have an effect too.

 

[jatoxico]

The pressure was probably falling when the OP was having this problem, not to say what Lumber Jack said couldn't have an effect too.

If you'll pardon the pun it's probably a perfect storm. In the am there is a call for heat so the oil burner has been recently running. The house is on the bottom of a hill and was on the leeward side of breeze coming off the LI sound. Stove itself is on the lower level with a clear shot up to the leaky pull-down attic stair. Throw in a little weather and voila. IDK, sounds good. Should start with an attic stair insulator. I need it anyway.