# Minimum chimney height?



## sparklow (Sep 8, 2011)

What does the group think on the topic of a minimum chimney height? I have been using twelve foot of prefab chimney for years and it works OK. I do sometimes wonder if a few more feet of chimney would increase the draft a bit. I don't get a lot of back puffing but it can be a little bit of a bother on a cold start. I see that some newer EPA stoves call for a minimum of 15 ft. of chimney - do I need to go higher?


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## pen (Sep 8, 2011)

If my father were here he'd tell you "If it's not broke, don't fix it."

If it were me, and it would be easy to put another piece on that chimney then I would.  You could pull the cap and even do a test w/ a piece of plain stove pipe shoved in there for a little bit to see how things go before you buy the permanent piece.

How far above your roof does it stick up now?  Would adding another piece require you to add bracing?

pen


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## Backwoods Savage (Sep 8, 2011)

Our chimney is nowhere near what is recommended plus we are surrounded by tall trees. In theory, it should not work. In practice it works just fine. On top of that, we live in MI and our chimney is a SS which runs up alongside the exterior wall with no chase. Why does it work when so many say it shouldn't? I know not why, only that it works fine.


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## sparklow (Sep 8, 2011)

Thanks for your answers so far. My chimney works as I said in my original post, I've just wondered if I could improve it without breaking the bank. I do appreciate all of your input.


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## Loco Gringo (Sep 8, 2011)

Spark, I too have only about 12 ft of flex liner and could use a little more draft. If I open my door all the way I get smoke. I plan to stick another 3 ft section of pipe up there before I light er up this year. I have 9 ft on hand just in case. Sit tight and if I dont need it all Ill gladly send ya a piece, you just cover the shipping.


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## cmonSTART (Sep 8, 2011)

Ya, if it's working for you and you're not putting your house in danger somehow I wouldn't lose sleep over it.  A few extra feet can make a noticeable difference though on cold starts and in marginal conditions.


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## nate379 (Sep 9, 2011)

I had 15 foot total last year and it didn't work well for me.  Wasn't bad when it was cold out, but it had almost no draft if it was over the low 30s outside or if it was humid.
This summer I put another 3 ft piece.  It's been in the low-mid 40s here and I have been burning small fires every couple days.  Seems to be working just fine, so I think I got it worked out.

There is no solid rule to chimney length.

My Dad has a stove in his workshop, chimney is about 20 ft total length (2 story building).  He had to put 2 dampers on teh stove pipe because there is that much draft with that chimney.  Can't even light the stove with teh drafts open because the match will go out.  It has sucked pieces of paper and cardboard out the top before even.

It's weird cause the house chimeny is about 40ft away about the same length and that one has never had a good pull on it.  It's ok, but I remember it being a pain when it was humid or warm, sometimes would want to backdraft even.

Had stoves in small sheds/ice fishing shacks that had maybe 5-6 feet of pipe and those worked fine.

Generally speaking though, taller is better.  I'd rather deal with having too much draft vs not enough.


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## begreen (Sep 9, 2011)

This varies from stove to stove. Some need more draft than others. It sounds like under certain conditions you are looking for improvement. Maybe this is during milder weather? If so, I would definitely consider adding another 2-3 ft to the chimney. One thing to remember is that the class A pipe needs a brace at 5ft above where it penetrates the roof.


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## jdinspector (Sep 17, 2011)

cmonSTART said:
			
		

> Ya, if it's working for you and you're not putting your house in danger somehow I wouldn't lose sleep over it.  A few extra feet can make a noticeable difference though on cold starts and in marginal conditions.



Good point about a few feet making a difference. The other morning, after one of our first fires this year, my neighbor commented about all of the smoke that my stove was producing. He said that he could smell smoke overnight in *his *house. It was very calm overnight. I'm sure that I have dry wood, a good combustor, and am burning correctly. However, my wife also commented about the smoke smell at grade level on our driveway during these marginal days (45 degrees outside at 7-8 am)

So today I went over and purchased two 3 footers of new chimney pipe and added one of them to the top. So far, it seems to be making a difference. I'll have to try for a few days before I make a final decision. I also have one additional 3 footer that I can add (one of the two that I bought today) if I need to add more height. I'm a little concerned about how it will look, as the current setup sticks up pretty high. With another 3 footer, there would be 15 feet of SS pipe sticking out of my roof vs. the original 9 feet that I had. I have some supports attached to the chimney, but they are very low on the chimney. Luckily, the new pipe interlocks with the old Simpson Duravent perfectly. It seems very solid.

Funny thing, I never had any smoke problems with the old stove (a VC Resolute Acclaim). Perhaps, the higher flue temps evacuated the smoke from the chimney faster? The current stove (A Woodstock Fireview) has flue temps at about 200 right now. The old stove would have had at least 300 degree temps under similar conditions.

Your comment about a couple of feet making a difference is correct for me. I think the 3 feet is making a difference!


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## stoveguy2esw (Sep 17, 2011)

some good advice in this thread , here's the poop.

generally stove manufacturers will recommend 13-15 ft my understanding is the 15 ft crowd measure from the floor of firebox while 13 foot group say from collar (pipe connection) at 12 ft you CAN generate enough differential of temp to create a working draft providing the 10-3-2 rule is in effect, however you uare at the BARE minimum to get away with it , this could be why you have sluggish starts. other issues such as altitude, tightness of the house location of zero pressure plane even the type of stove can be factors but with the only issue being slow startup performance and the fact you have not reported backpuffing in adverse weather and not so cold days in the main body portion of the burn cycle , i think the addition of 1 to 2 ft of class A pipe at the top would make it virtually perfect. i doubt you would need more than that


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## sparklow (Sep 17, 2011)

My original query stated that I have 12 ft. of prefab chimney and this true, but I also have three ft. of vertical stove pipe from the top of the stove before the prefab chimney pipe. Am I correct in assuming that this should also be included in determining a "total" height? If so than I am at 15 ft. Sorry if this sounds like a newbie question, the sad fact is that I'm an oldie, been burning for over thirty years!


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## Backwoods Savage (Sep 17, 2011)

From one oldie to another, yes, that 3' of vertical should be included for measuring the total height.


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## tfdchief (Sep 17, 2011)

sparklow said:
			
		

> My original query stated that I have 12 ft. of prefab chimney and this true, but I also have three ft. of vertical stove pipe from the top of the stove before the prefab chimney pipe. Am I correct in assuming that this should also be included in determining a "total" height? If so than I am at 15 ft. Sorry if this sounds like a newbie question, the sad fact is that I'm an oldie, been burning for over thirty years!


Yes, that is included.  Some manufactures even measure to the bottom of the fire box.  Whoops, BS beat me to it.


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## rottiman (Sep 17, 2011)

I have 12' of SS liner in my masonry chimney.  I ran my regency R-3 on it for 10 years and is functioned A-1.  In fact, when the draft was extreme I ended up installing a in line draft plate.

Two weeks ago I installed my Timber Ridge 30 and hooked it up to the same liner.  The difference in performance was unbelievable.  I had a hard time getting it started when the temp was above 50 degrees, smoke rolled out the door each time it was opened and the overall performance of the stove was obviously no where near what this heat monster should be doing.  Soooo, after reading about this earlier today while @ work, I stopped on the way home and picked up a 2' section of regular 6" stove pipe.  went up and put her on and it immediately made the stove perform as you would expect it to.  Amazing what that 2 additional feet of pipe did for this set up.  The only downside to it is that now I have 4' of 6" pipe sticking out of the top of my fieldstone chimney, but I am really gonna enjoy this stove when the cold really sets in.


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