Getting Smoked out of Basement

[Hunt]

Hi, new to the site and seeking advice.

My family and I live in MT and just embarked on replacing our wood burning stove as well as demoing our CMU chimney and replacing it with a stove pipe for the stove.

All work was done professionally and I’m seeking advice on why my family is getting smoked out of our house. The stove is a supreme novo 24 and has about a 3’ rise before it 90s to a thimble and then up the backside of the garage to the top of the second story. The Wood that we used for burning is seasoned and we have tried everything from cracking windows to get fire started to relief any negative pressure, to opening door ultra slow when fire is good and hot.

We had the vendor out today and he wants to help make it right but we still have an expensive stove and pipe that smokes us out. Is this just the physics of having a stove above grade in the basement? Or is this because of the 90 degree turn? Or is it a stove issue? Long time user of wood burning fire places.

Note that the garage side of the stove pipe is framed in and insulated and the exposed pipe along the exterior of the house will soon have a chimney chase.

Thank you for any help you can provide.

 

[Hunt]

Worth noting that my chimney guy was here for over an hour getting the stove up to temp. It took a long Smokey time to see it hit the orange with seasoned wood. He agreed it smoked the house too much, but now I’m stuck holding the bag. Would a stove with less automatic features like a blaze king be a better fit?

The old stove that was there before this novo 24 was a 90s stove that was drafty, even though the old flue tiles were cracked where air could escape theoretically should have made it less Smokey. I’m determined to figure this out, my gut says it’s the stove. Also saw something about a draft fan could help?

 

[xman23]

Is bad draft just during startup?

 

[BKVP]

You may want to add some additional length to the chimney...but first, does the cap have restrictions like a band or spark arrestor screen? What is your elevation? Your class A exposed section may need to be enclosed. Can you or have you run a F/A kit to the stove without going above bottom of firebox?

BKVP

 

[stoveliker]

You say basement; is the stove on a floor below the garage entrance or at the same level as the garage entrance door?

 

[EbS-P]

Does cracking the nearest window have any effect on the draft?

 

[kborndale]

You say you are using seasoned wood, how did you determine that?

 

[Hunt]

Is bad draft just during startup?

Startup and everytime the door opens even when the fire is good and hot.

 

[Hunt]

You may want to add some additional length to the chimney...but first, does the cap have restrictions like a band or spark arrestor screen? What is your elevation? Your class A exposed section may need to be enclosed. Can you or have you run a F/A kit to the stove without going above bottom of firebox?

BKVP

The chimney length is pretty significant, and extends about 3-4’ at the top of the roof. I thought of the FA kit but there would be no way for the FA kit to stay at the same level I.e it would have to be higher than the FA insert which wouldn’t be allowed and would likely push more smoke into the room.

 

[Hunt]

You say basement; is the stove on a floor below the garage entrance or at the same level as the garage entrance door?

Yes the basement floor is below the garage floor by about 28 inches.

 

[Hunt]

Does cracking the nearest window have any effect on the draft?

Slightly, we even had the garage door open to help with the smoke. The only time we got it not to smoke was when the window to the basement was open as well as the garage door. Fast forward to winter and I’m imagining this is not sustainable in negative temperatures.

Hardwood that is seasoned has a better effect on the stove obviously, but even that made the house smoky just on a lesser scale. but I’m suspicious of the automatic ‘reduced’ air intake design of this stove that was recommended by the chimney vendor and that it may not be best for a negative pressure room like a basement. Our house is 80s construction but is tight.

I’ve been reading tons of information on the BK princess and I see other fellas have a similar basement with a wood burning stove and they’re not getting smoked out of their home. So my theory is the stove but I could be wrong.

 

[stoveliker]

It's not as tall as I thought; it's not basement + first floor + second floor. Instead it's (optimistically) 4 ft above the roof + 8 ft 2nd floor + 8 ft first floor = 20 ft. But then we have to account for the 2x45s and a 90 elbow, as well as the horizontal run.
Generally a 90 elbow adds 2 ft to the recommended minimum flue height, the 45s together too I believe. The horizontal run of, say, 2 ft, would add 4 ft to the minimym recommended height.

AND then there is elevation: you're in Montana, so possibly higher up. For every 2000 ft of elevatino above sea level, one generally has to add a ft of length to the minimum recommended flue heigh.

Assuming you're at 2000 ft, that would add a total of 2 + 2 + 4 + 1 = 9 ft to a minimum recommended flue height.

Most stoves want 15 ft. I don't know your stove's recommended minimum, but it's worth looking that up.

You're at 20 ft I estimated above, but the effective height is only 11.

I second BKVPs suggestion to add height.

You can do so by adding some single wall stove pipe as a test. If that works, buy class A pipe to add. (And possibly a brace as each 3 ft above the roof penetration needs a brace).

 

[EbS-P]

I will add negative pressure in the basement can be due air leaks in the upper floors. Hot air out creates the negative pressures down lower. Time for a home energy audit to find leaks and try another few feet of pipe.

 

[bigealta]

Agree with adding a temporary single wall pipe to the top. Cheap and easy test. Get 2 or 3 sections and add 1 at a time to test. Big box stores usually have them in the back, but this time of year maybe not?

 

[bigealta]

Also do Top down starts. They produce much less smoke on start up and get your secondary flames going faster.

 

[Hunt]

Thanks for the responses. I think the negative pressure issue is because the home is so tight. I've already taken a thermal gun to most of the house and cant find any deficiencies. For what its worth the home is well insulated because having temps of -40 in the winter will make you learn quickly.

Regarding the flue, It says 'the minimum height for venting from the base of the unit is 15'. I'm at about 4000 feet, so that would mean i'd need to have a total flue height of 19' i'm assuming? Right now, I have about an 18.5' flue, the section on the second story roof sticks out 3.5'. I can't imagine running a taller pipe with this run? But is the suggestion to run an additional 3 feet on top of the 3.5' already on there? I'm just having a hard time wrapping my head around that unless a giant were to put that pipe run on.

Looking in the install booklet there are a few things that i might be over analyzing

particularly # 2 (i'm in montana) #6 (flue goes through garage attic) #9 (pipe makes two 45's)

i'm just speculating that maybe this stove doesnt work as well with the two 45's and prefers a straight run with its automatic decreased air intake on combustion. But i don't know, stop me if i'm wrong. Something just seems off.

 

[bigealta]

The fact that it took an hour for the tech guy to get the fire going says to me your wood is not seasoned enough or you have a major defect in the piping.

Did the old stove smoke out the house to?

 

[Hunt]

@bigealta i read your post about your pup and i wanted to express my condolences for your loss. I had to put my 14.5 malamute down in January and it was one of the harder things i've had to do. I still miss him and so do my kids.

 

[Hunt]

The fact that it took an hour for the tech guy to get the fire going says to me your wood is not seasoned enough or you have a major defect in the piping.

Did the old stove smoke out the house to?

He was baffled (no pun intended) by the long startup time also. He brought seasoned hardwood, so the moisture testing would have been on his watch. He's been around for a while.

 

[bigealta]

The way to burn modern stoves is:
Start with a top down set up.
Do not open the door again until it's burned down to hot large coals.
Reload on hot coals and close the door.
Do not open the door again until you have large hot coals again.
Reload on hot coals
Close to door.

the old way of raking the fire and playing with the splits and throwing in splits whenever you feel like it are over.

 

[bigealta]

@bigealta i read your post about your pup and i wanted to express my condolences for your loss. I had to put my 14.5 malamute down in January and it was one of the harder things i've had to do. I still miss him and so do my kids.

Thanks. Yes it's such a brutal event.
I flew to Houston, Tx and rescued these 2 guys in Late February, rented a car and drove them home to NJ.
Our other dog was rescued from Houston as well so it felt right.

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[stoveliker]

Thanks for the responses. I think the negative pressure issue is because the home is so tight. I've already taken a thermal gun to most of the house and cant find any deficiencies. For what its worth the home is well insulated because having temps of -40 in the winter will make you learn quickly.

The thermal gun is not the right tool; yes air leaking in will make things colder, but it's a blower door test that matters. In particular on the upper floor (leaks into the attic or windows there).

However, if opening a window (as a test - I understand that's not a viable way in general when it's cold) does not help, it's not a negative pressure issue.

Regarding the flue, It says 'the minimum height for venting from the base of the unit is 15'. I'm at about 4000 feet, so that would mean i'd need to have a total flue height of 19' i'm assuming? Right now, I have about an 18.5' flue, the section on the second story roof sticks out 3.5'. I can't imagine running a taller pipe with this run? But is the suggestion to run an additional 3 feet on top of the 3.5' already on there? I'm just having a hard time wrapping my head around that unless a giant were to put that pipe run on.

If you're at 4000 ft, 2 45s, and a 90 (in the garage), you need 10 ft (2+2+4+2) above the recommended height, i.e. 25 ft in total.
Yes, you would need quite a bit more height to meet the minimum. However, I'd go by sections, as suggested above. Just add until you see that it works and forget about the theoretical recommendations.

Looking in the install booklet there are a few things that i might be over analyzing

particularly # 2 (i'm in montana) #6 (flue goes through garage attic) #9 (pipe makes two 45's)

Insulating the pipe will surely help draft. The pipe makes 2 45s in the room AND a 90 in the garage.

i'm just speculating that maybe this stove doesnt work as well with the two 45's and prefers a straight run with its automatic decreased air intake on combustion. But i don't know, stop me if i'm wrong. Something just seems off.

 

[Hunt]

The easiest way I can explain this is when the fire was hot and running ambers and smoke wanted to leave the firebox as soon as the door open (slowly and patiently) and once a bed of coals was established. I did manage to get a few times of feeding the fire that did not yield smoke, and i understand new stoves are more finicky but it was enough for my wife to say "we should have got a gas fireplace".

The vendor made a comment about it also, its like the cold air continues to push down on the flue and out into the basement even when the fire is hot and going.

So looks like off to the hardware store I go to try and add 3' more. Since no one has mentioned the stove, is it safe to rule that out as not a factor?

 

[bigealta]

If you add say 6 ft of pipe and it has no effect then i would look at the stove. A couple people here have switched stoves and had much better results. Not sure about your model?

 

[stoveliker]

I do not know your stove, so i can't say anything about that.
It is true that some stoves are more demanding in adherence of flue height guidelines than others. So it could be a combination of the two - if your stove is not as easy breathing combined with the fact that you're short on flue height can result in the symptoms you have.