Flue question for coal/wood stove.

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

Stevejo

New Member
Mar 23, 2023
23
Ky.
Hi all. New member and have a couple questions, if anyone can help.
Just got an old wood/coal stove I’m going to put in my basement. I had the house built a couple years ago and had the appropriate double wall flu/chimney/pipe installed when built so just have to connect it.
The double wall goes through the main floor and on into a bonus/attic room.
Can I remove a section of the double wall for heat reclamation? Or even cut a section out or cut holes to put in one of those heat powered fans?
Kinda same question for the main floor section which is in a …chase?.., could I vent that and do the same for heat on the second floor?
I’ve read through and searched but couldn’t find anything specific. I did see the info on the flu not maintaining a good operating temp and creosote build up, but would that be a problem with coal?
Thanks.
 
Hi all. New member and have a couple questions, if anyone can help.
Just got an old wood/coal stove I’m going to put in my basement. I had the house built a couple years ago and had the appropriate double wall flu/chimney/pipe installed when built so just have to connect it.
The double wall goes through the main floor and on into a bonus/attic room.
Can I remove a section of the double wall for heat reclamation? Or even cut a section out or cut holes to put in one of those heat powered fans?
Kinda same question for the main floor section which is in a …chase?.., could I vent that and do the same for heat on the second floor?
I’ve read through and searched but couldn’t find anything specific. I did see the info on the flu not maintaining a good operating temp and creosote build up, but would that be a problem with coal?
Thanks.
No you cannot modify the chimney pipe at all. You can vent the chase if you want.

Are you sure your chimney is the proper alloy of stainless for use with coal?
 
No you cannot modify the chimney pipe at all. You can vent the chase if you want.

Are you sure your chimney is the proper alloy of stainless for use with coal?
I did specifically tell the people that installed it that it would be for a coal stove, so I’m assuming it is. I have the installation paperwork somewhere, I could double check it though. It’s shiny like stainless is all I can tell you personally. Would there be any kind of data stamp on it?
 
No you cannot modify the chimney pipe at all. You can vent the chase if you want.

Are you sure your chimney is the proper alloy of stainless for use with coal?
Or maybe take a few pics? Most of it is easily accessible. If that would do any good.
 
If there is a tag on the pipe that identifies it that would help
 
Or maybe take a few pics? Most of it is easily accessible. If that would do any good.
Pictures are welcome. The brand of chimney pipe would also be. The chimney pipe can not be violated or tampered with. The chase could have an upper and lower vent grille installed to vent some of the trapped heat into the room.

The questions sound more about heat distribution. What stove model is this and how large of an area is it heating?
 
If there is a tag on the pipe that identifies it that would help
Seems like the pipe is adequate.

55AE8A03-185A-410F-BA23-94DC807FE165.jpeg 9CB77181-5613-47A2-A5C7-7B642D91167A.jpeg 10A831DF-E51F-46CB-8A12-F8BC3993DEB3.jpeg
 
Pictures are welcome. The brand of chimney pipe would also be. The chimney pipe can not be violated or tampered with. The chase could have an upper and lower vent grille installed to vent some of the trapped heat into the room.

The questions sound more about heat distribution. What stove model is this and how large of an area is it heating?
The stove is a “Florence hot blast”. Seems in good condition but no firebrick. I’ll have to get some for that.
No idea on the model number. Was hoping someone here could help me identify or find where that data would be on the stove itself. Pics attached.
2200 sq foot on basement, but fully insulated with closed cell polyurethane. (Anywhere above the ground line anyway)
Will just be for periodic/emergency use mostly. Maybe run it during an unusual cold snap in the single digits to keep that utility bill down.

C82547DE-E80D-42D7-AD97-FA77A679FD35.jpeg 8B04DFEE-5388-4081-BFE3-D266350685DF.jpeg 9BDC5E04-2BE5-484F-8A1B-BB70B7BBE1CA.jpeg
 
And is there a space between the pipe and that plate on the attic floor?
 
That pipe is 430 inner wall it won't hold up all that long to coal useage.
What would be the best material to use for wood/coal ? Or a better manufacturer?
The good news is that the entire thing is fairly easy access. I’m sure the cost will be the bad news.
 
What would be the best material to use for wood/coal ? Or a better manufacturer?
The good news is that the entire thing is fairly easy access. I’m sure the cost will be the bad news.
It should be at minimum 316 inner wall but better if it was 316 inner and outer.
 
  • Like
Reactions: Stevejo
Looks like there’s a space that’s been filled with some kind of sealant? Wasn’t too impressed with that myself.
It should really have an attic insulation shield with a storm collar over it
 
  • Like
Reactions: Stevejo
It should really have an attic insulation shield with a storm collar over it
I’ll have to do a little self educating on this and go look and see exactly what it has. There’s a plate with a ring in the floor that the pipe goes through. I’ll get back with you when I figure what I actually have.
 
It should really have an attic insulation shield with a storm collar over it
Ok. Now that I know what those things are, I went and looked. Took some pics.
I don’t think it has a proper “attic insulation sheild”, but it does have those metal plates and is “chased” in at the attic, or possibly a continuation of the chase on the floor beneath it. Sorta both maybe. The boroscope didn’t really give me a defining enough view to tell.
Think I have the storm collar ok though.
May seem like an unusual configuration because of the roof being foam insulated though.
Take a look and tell me what you think.
Should I put an attic insulation sheild in or just maybe some ceramic fiber insulation in the “chased” area?
Was also thinking maybe put some of that rock wool in the storm collar as well, because that attic area is actually a bonus room. (Not completed. Just had all the stuff roughed in for later convenience. Was bleeding too much cash into what was starting to turn into a money pit)

A4203492-7E61-40F9-81AC-9A3ADBB2D01B.jpeg 2A28EDF8-9918-4FBB-8858-E7AF0913C3F9.jpeg E551F2FA-2B0E-4CC3-B8E1-0D28E842CA44.jpeg
 
It should really have an attic insulation shield with a storm collar over it
To clarify, that first pic showing the attic insulation sheild (maybe)
There’s the top plate with hole (obviously) and another like it on the bottom side.
On the ceiling of the floor beneath it.
Pipe goes between two joists and is closed in by another 2 added sections of 2x8 to make a little boxed area. That all sits on the chase below it, or is a continuation of it.
But no metal sheilding the pipe.

B292B20D-4E76-4959-829D-25A8D51BCA16.jpeg
 
To clarify, that first pic showing the attic insulation sheild (maybe)
There’s the top plate with hole (obviously) and another like it on the bottom side.
On the ceiling of the floor beneath it.
Pipe goes between two joists and is closed in by another 2 added sections of 2x8 to make a little boxed area. That all sits on the chase below it, or is a continuation of it.
But no metal sheilding the pipe.

View attachment 311415
Yeah that gap needs to be covered. It also really doesn't look tall enough in reference to the roof
 
  • Like
Reactions: Stevejo
It needs to be 2 ft above the nearest roofline.

10-3-2 rule.JPG

The attic insulation shield typically would be on the attic floor surrounding the chimney, but it looks like the insulation at the underside of the roof. If this is a conditioned space that is actively used then the pipe should be chased or at least protected from anyone ever inadvertently laying something against the chimney pipe.
 
It needs to be 2 ft above the nearest roofline.

View attachment 311419

The attic insulation shield typically would be on the attic floor surrounding the chimney, but it looks like the insulation at the underside of the roof. If this is a conditioned space that is actively used then the pipe should be chased or at least protected from anyone ever inadvertently laying something against the chimney pipe.
The lack of chase can be explained by the fact that the room was left unfinished. But good to know that it’ll need to be chased if/when it does get finished. I kinda eyeball measured the chimney placement and I think they got around the 3-2-10 rule because it is 3 ft tall and is more than ten feet away from any roof peak. The pic angle probably didn’t show this very well.
As a general rule should it be higher anyway for better performance/safety?
Probably going to change the entire thing out and replace with all Ventis stuff anyway. Seems like it’s the only manufacturer that offers 316L on both sleeves and is insulated.
I should be dead before that pipe wears out, which would be my goal.

Even though it’s “chased in” where it goes through the attic floor I’ll probably just put an attic insulation shield in to be sure with some ceramic fiber filling the outer space.
Good info. Thanks.
It needs to be 2 ft above the nearest roofline.

View attachment 311419

The attic insulation shield typically would be on the attic floor surrounding the chimney, but it looks like the insulation at the underside of the roof. If this is a conditioned space that is actively used then the pipe should be chased or at least protected from anyone ever inadvertently laying something against the chimney pipe.