Double or single wall pipe?

[enigmablaze]

Strangely I couldn't fine a thread about this on here! I had assumed we would just do double-walled black pipe if we install a stove, however the stove we favor (Morso 1440) doesn't change it's "to corner" clearances for single vs double wall pipe...so I'm beginning to wonder if it's worth the extra money?

Does it have significant benefits? We are planning on the dual wall class A obviously for the chimney part but for the stovepipe inside I'm not sure any more? It's only one story for the location we're thinking so the cost savings wouldn't be strong either way. Also I don't like the idea of putting a probe thermometer into a double wall pipe...I'd much prefer a magnetic thermometer which I believe is only an option on single wall.

 

[begreen]

Yes, besides closer clearances double wall stove pipe keeps flue gases hotter thus improving draft. With a shorter chimney this is a good idea.

 

[enigmablaze]

Yes, besides closer clearances double wall stove pipe keeps flue gases hotter thus improving draft. With a shorter chimney this is a good idea.

Haha well you know I'm concerned about the draft already ! Sounds like that is the best choice for me then.

Do you think a stovetop thermometer is as good as a flue thermometer? I really hate to install a probe thermometer in there Would it detect overfiring as well?

 

[firefighterjake]

Double wall . . . better clearances, better drafting generally and they tend to hold up better than most single wall.

Installing the probe thermometer is really not hard to do.

 

[EatenByLimestone]

Not knowing you specific situation, I'll throw out an advantage to the single wall.

It'll radiate more heat. A big room, or even a small room that needs to heat up fast could benefit from single wall providing an additional heating surface. This can be more important with a small stove.

 

[kennyp2339]

Not knowing you specific situation, I'll throw out an advantage to the single wall.

It'll radiate more heat. A big room, or even a small room that needs to heat up fast could benefit from single wall providing an additional heating surface. This can be more important with a small stove.

You heat the room with the stove, not the chimney, the chimney is the engine that drives the stove, so if your already running on the lower end of the draft spectrum, double wall pipe will help improve your draft by keeping flue gases hotter, also you wont have as much condensation of smoke reducing the creosote build up chances.

 

[Highbeam]

One other big reason to use double wall is that the interior wall of double wall pipe is stainless steel just like your class A. It will last a lifetime.

I installed cheap single wall for my shop stove and the black paint fades and oxidizes due to the high heat. The outside of my double wall chimney in the house still looks like new.

The double wall stuff is welded, smooth, seams compared to the ugly and loose seams and connections made with most single wall which is snap lock.

Yes, get double wall. Install the condar probe. It's super easy and measures actual flue gas temperatures so you can be sure not to exceed 1000 degrees.

 

[xman23]

Mine is single wall up to the ceiling box. The total length, inside single wall and outside double wall is 21 ft. About 7 ft of it single wall inside. Yes the single wall does radiate some nice heat. In my case not enough the starve the double wall of enough heat to creosote up the top of the chimney. The magnetic thermostat on it normally indicates about the same as the stove top. It is a straight shot up from the stove, which does help with the draft and cleaning.

I recall the guys explaining chimneys at the Washington DC hearth guys meet up a few years ago, saying. The chimney height does not include the single wall section that connects to the double wall. It didn't make a lot of sense to me, so maybe some of the experts that were there can chime in.

 

[enigmablaze]

Gotcha.
I'm slightly concerned even a stove this small might prove to be a little powerful for the size room it's in so gaining extra heat from the chimney isn't a big gain for me...that is a good point though!

Can anybody weigh in on this. I'm concerned about the draw for this stove, I'm hoping I can get a total stack of 13'+ (this will require about 7'+ above mostly flat roof, ugh). This is a single story addition next to a 1-1/2 story house and our house is also in an old creek valley so my neighbor right behind me is also higher than me etc. and quite close. We can try to get the stack as tall as possible and we do not need any turns in the pipe, but I AM debating strongly whether to vent out the back with a T (partly for cleaning but because the stovetop use is very important to me) or top.

SO...what do you think is more important for draw?
Top or back venting
Height of piping
Double or single pipe

Obviously a 16'+ chimney with double pipe out the top with no trees or houses around would be lovely but if you have to give one, what is the least important? Am I missing anything else I can do?

 

[begreen]

Kind of has been already asked and answered, no? top vent, with double-wall pipe with total flue of at least 14' is what has been suggested for best performance. You can try the tee out the rear. It might work ok or it might work poorly. This can be a function of local terrain as much as the flue. If it drafts poorly at say 40º then add another 2-3 of pipe and a second brace.

Or put a bigger stove at location #2 and do it proper.

 

[enigmablaze]

Kind of has been already asked and answered, no? top vent, with double-wall pipe with total flue of at least 14' is what has been suggested for best performance. You can try the tee out the rear. It might work ok or it might work poorly. This can be a function of local terrain as much as the flue. If it drafts poorly at say 40º then add another 2-3 of pipe and a second brace.

Or put a bigger stove at location #2 and do it proper.

Hahaha, begreen you've been very patient with me You know I'm trying so hard to make that rear-vent ok ! Would it be a big deal to install it that way and change it later if it was a bad idea? I don't have a hearth to change etc. since it would be on concrete.
Haha that #2 spot would be sweet but the $$$ is just

 

[begreen]

It sounds like you are determined to try the small stove in the sunroom rear-vented so install it however you like. Just be sure that the flashing on the rubber roof is done correctly and the chimney is properly braced and the proper clearances for stove and for the stove pipe are honored.

Me, I'd put a bigger stove in spot #2 and I'd skip the chase this season. The stack outdoors will be much shorter, no brace needed and you'd be heating most of the house with normal length splits. Otherwise I am willing to bet you'll be wanting to do this after a year of burning. Then it will cost twice as much.