Steel Chimney?

I had a thought today & would like to see if this thought has ever been thought, or better yet, has the idea ever been tried & what were the results?

Would 6" schedule 40 steel pipe make a working chimney?

yup. many people in the adirondacks use this appoach and usually it's located outside the home too. not a big deal if you have a chimney fire, the pipe is thick and it's four+ feet from the home. I've even seen it where people will collect the buckets of liquid creosote that condenses out of the bottm and use it to "paint" barns and fences etc. the next summer.

I helped a neighbor build his out of a 30' chunk of 1/4" wall 12" steel box section. he stood it up about a foot and a half from his house and piped his woodstove into it.

Berlin wrote:buckets of liquid creosote

Ewwwww, how gross is THAT? Yuccck!

Of course this will be for coal, no creosote. Unless someone has a reason that I just shouldn't, I'm going to give it more concideration. It would be quick and might actually look better. Paint it black & the small physical size would make it less conspicuous. Going in the outbuilding will have most all of it in the air. Put some big bolts in the form before the concrete is poured, weld a square plate on the bottom, stand it up, bolt it down. Hmmmmmm

Might 7" be better or worse than 6"? I have easy access to either.

I have been giving this some thought for a few years now as I want to get off my short, exterior chimney.

I would match it to the flue size of the stove for proper draft. You could experience "down drafting" with exterior uninsulated pipe like that drawing smelly chimney air into the room when the stove is not in use. Otherwise I think it would work.
By the way, how do you insulate it through the wall and connect it to the stove?

Many steel pipe chimneys in my area. Most are old pieces of oil well casing. They usually make a wall thimble from a larger piece of furnace duct pipe placed over the horizontal section af chimney and refractory cement. Some just put the steel pipe through the wall.

I thought if the pipe was not insulated the cold pipe would not draft properly?

It drafts better warm, that is why when you look at a house built before gas/oil heat (forced draft), they had the chimney in the middle of it. The forced draft appliances do not need a chimney that drafts, so they ruined a lot of Forum members fun by putting chimneys on the outsides of homes. But you don't need anything but height to get a draft. Picture a pipe 50' tall, at the bottom the air pressure (atmospheric) is say 14.2 PSI. If you go up 50' to the top, you will find the air pressure at say 14.0 PSI. Inside the pipe the atmospheric pressure wants to equalize throughout the pipe and it will draft from top to bottom attempting to equalize but never doing so. So the key to draft is height. Heat, diameter and a few other factors play in as well as what you have hooked up to the chimney, height makes it happen.

Freddy, I'm not sure what it is you call schedule 40 but I used 16' of 8" heavy walled drainage ditch pipe, the one with the ribs. It is corroding severely. Don't think it will last more than a couple years. It originally was serving a wood boiler. Draft is a problem. It works sometimes, not others. I would only recomend using the pipe outside as a last resort. Too many of my friends have been turned off to coal by venturing into the boiler room when the draft isn't working. Maybe one pipe inside of another might work better.Not meaning to offend you but,,, Seems a shame to put so much excellent work into a project to finish it with a rinky dink chimney. Scott

coaledsweat wrote: So the key to draft is height. Heat, diameter and a few other factors play in as well as what you have hooked up to the chimney, height makes it happen.

So my 45 foot high chimney through the center of my house should draft well?

I think the pipe Freddy is talking about will work better than the drainage pipe in the previous post. The steel pipe Freddy is talking about is very heavy and thick walled, probably .080-.100" thick. Also the pipe is smooth bore vs. the ribbed of the drainage pipe. I think the ribbed would create some turbulance causing less of a draft. If the pipe is painted or coated somehow, I don't see why it wouldn't last for many years. I don't think the steel in the stoves is much thicker and it lasts for many years as long as it's taken care of. Just my 2 cents for what it's worth.

Jeff

The schedule 40 pipe has 1/4" walls.

Scott...add more heght! 16' isn't very tall. I do appreciate your words.

cArNaGe wrote:So my 45 foot high chimney through the center of my house should draft well?

It should suck the skins of the bananas in the kitchen!

Schedule 40 6" pipe has a wall .280' thick, 20% thicker than .250".
20' is generally the minimum height you want for a chimney, 16' is going to have issues more often than not.
Speaking of issues, a 45' chimney through the center of a home is going to have some too. You may need a barn door for your baro.

I just thought of something. You know those systems that blow air from the cellar floor out a window to freshen the homes air by drawing air down through the home from the attic and expelling it at the cellar to keep mold and damp down? With a chimney like that, you could just open the cleanout in the summer and bingo!

I`m by far not an expert on the draft. The only concern that I would have is a heavy enough base plate & footer. It might just be me but being a retired ironworker I always tend to over build just to be on the safe side. As long as all things are considered as wind & the possibility of someone perhaps hitting it with a vehicle or riding lawnmower it should work fine.(I mention the mower because my wife has run down some small trees already)