Flue size

Motowiz1 · Post by **Motowiz1** » Wed. Jan. 10, 2018 8:59 am

Hi everyone,
I have been away a while and changed my username . I have changed my email so I could not sign in under old one Motowiz. Anyway l would appreciate if you guys could give me some advice. I moved into a new house and I would love to put a coal/wood stove in my finished basement. I am looking at the ds comfort max 75?? I have had many opinions on the chimney flue size. This stove has a 6” top outlet. I have a square 12” clay masonry chimney about 25’-30’ tall. The chimney is on the inside of my house and sticks out of my roof maybe 4’. Would this draft good? I am told I will have lots of problems unless I put in a ss liner. It is against my judgement to not use this chimney the way it is. Liners seam to me a fix for a bad chimney?? Is someone trying to make quick money on me?

lsayre · Post by **lsayre** » Wed. Jan. 10, 2018 9:07 am

What you describe (a clay or terracotta lined brick chimney) should be fine as is, as long as an inspection proves it to be sound.

McGiever · Post by **McGiever** » Wed. Jan. 10, 2018 9:17 am

Your good!
Being inside at constant room temp or better and with 25-30 feet of height has a lot going for it.
The opposite, outside wall and shorter would be trouble for sure.
Liners and coal are not a good combination anywhere anytime due to rotting and eventual collapse and blockage.

Do not belieive the warranty hype.

Post by **coaledsweat** » Wed. Jan. 10, 2018 9:25 am

The chimney thimble should be sized the same as the appliance's breech. Avoid any metal liner. Chimney sounds good to me.

freetown fred · Post by **freetown fred** » Wed. Jan. 10, 2018 9:43 am

Indeed they are M!! If ya want, take a mirror & look up the chimney--if it's not blocked in any way, you're good!!

Motowiz1 wrote: ↑
Wed. Jan. 10, 2018 8:59 am
Hi everyone,
I have been away a while and changed my username . I have changed my email so I could not sign in under old one Motowiz. Anyway l would appreciate if you guys could give me some advice. I moved into a new house and I would love to put a coal/wood stove in my finished basement. I am looking at the ds comfort max 75?? I have had many opinions on the chimney flue size. This stove has a 6” top outlet. I have a square 12” clay masonry chimney about 25’-30’ tall. The chimney is on the inside of my house and sticks out of my roof maybe 4’. Would this draft good? I am told I will have lots of problems unless I put in a ss liner. It is against my judgement to not use this chimney the way it is. Liners seam to me a fix for a bad chimney?? Is someone trying to make quick money on me?

michaelanthony · Post by **michaelanthony** » Wed. Jan. 10, 2018 11:31 am

Digital C.O. monitors, 25' - 30' clay lined chimney, and a coal stove is a recipe for comfort!

keegs · Post by **keegs** » Wed. Jan. 10, 2018 11:37 am

FWIW... I've been told not to reduce an 8" stove exhaust vent to 6" flue pipe.

I don't think it's a problem to run a 6" stove exhaust vent into a 12" flue.

Sunny Boy · Post by **Sunny Boy** » Wed. Jan. 10, 2018 1:00 pm

With my brick chimney, the unlined flue is 2-1/2 times bigger area in cross section than the 6 inch stove pipe thimble that was still plumbed into it from the late 1800! With the small firebox of my range and it's 6 inch pipe, the chimney still drafts very well.

Paul

gardener · Post by **gardener** » Wed. Jan. 10, 2018 3:32 pm

Reads like most everyone responding is in favor of exhausting to a larger brick or clay flue than to the same flue size if rigid or flexible metal flue.
Is not the temperature of the exhaust and the shape of the chimney significant factors?
At least what I have read for wood burning, round flues of the same diameter offer the least resistance from eddies, yet many/most chimneys are square or rectangle, some with offsets.
With coal exhaust the main goal is to expel the carbon monoxide?
The fly ash can build up, but that would be swept out with annual maintenance... correct?

McGiever · Post by **McGiever** » Wed. Jan. 10, 2018 3:58 pm

gardener, Chimneys come in many flavors, the OP's being inside the building and tall enough negates some of those generic concerns, as the preceding listed testimonies prove out.

And wood and it's problematic condensing creosote is a different animal all together.

Sunny Boy · Post by **Sunny Boy** » Wed. Jan. 10, 2018 5:29 pm

McGiever wrote: ↑
Wed. Jan. 10, 2018 3:58 pm
gardener, Chimneys come in many flavors, the OP's being inside the building and tall enough negates some of those generic concerns, as the preceding listed testimonies prove out.

And wood and it's problematic condensing creosote is a different animal all together.

What Mac said.

To prevent creosote problems with wood, it is fussy about it's chimneys size and how well it retains heat. But coal does not form creosote, so it is more forgiving of chimney over-size and can work fine at much lower chimney temps than wood can. As long as the chimney is warmer than outdoors it'll draw with coal.

Paul

Motowiz1 · Post by **Motowiz1** » Fri. Jan. 12, 2018 9:52 am

Thank all of u for the advice It is appreciated! Now I need to get the thimble installed. I can’t wait to get a stove going. I went and looked at the ds comfort max it looks very heavy duty. The Amish man had great things to say about it. Of course he is a sales man. Does anyone have one here?

coalfan · Post by **coalfan** » Fri. Jan. 12, 2018 12:10 pm

messick stove you tube will help you give that a shot !!

McGiever · Post by **McGiever** » Fri. Jan. 12, 2018 11:11 pm

Motowiz1 wrote: ↑
Fri. Jan. 12, 2018 9:52 am
Thank all of u for the advice It is appreciated! Now I need to get the thimble installed. I can’t wait to get a stove going. I went and looked at the ds comfort max it looks very heavy duty. The Amish man had great things to say about it. Of course he is a sales man. Does anyone have one here?

Where did you look at them at?

lsayre · Post by **lsayre** » Sat. Jan. 13, 2018 6:17 am

I have a ComfortMax 75, but to date I have only burned wood in it, so I can't comment as to its characteristics with anthracite or bituminous.

When I purchased it, it was being marketed as a wood/coal stove. But recently DS Machine has been forced (presumably by the EPA) to market it as a coal only stove (as confirmed in a phone conversation I had with them only about a week or so ago), and as can also be confirmed on their website.

The stove is built like a tank. Rock solid, and just under 600 lbs. There is no faulting the construction. I've had no previous coal stoves to compare it to, but I'm very happy with mine.