Thru the Wall or thru the roof?

[eustis22]

I have constructed a new shack and am ready to install the stack after placing my Mason 2X3 18" from my wall. I am wondering what the draft (and boiling) implications would be if I ran my stack thru the wall and up instead of up thru the roof? In both cases there is a 90-degree angle involved, either right off the stove or after the pipe passes thru the wall. I assume I would need to double wall the stack wherever it is next to the wall (already have one section for going thru the roof). Would that extra 24 inches of horizontal stack negatively impact my draft? I do have AUF.

[buckeye gold]

From everything I have ever read or been told the height of your chimney is more critical then having an elbow or two. If in doubt just go a little higher. I have checked draft with a steaming pan of water before, or a smoking paper roll. Once you have your pipe up hold the pan right under the pipe where it goes into firebox (Before you attach it of course). It should pull the steam or smoke into the pipe fairly quickly. The farther you can pull the pan away and get draw the stronger your draft but it won't be far. You will probably have to be right under it if your shack isn't heated, because the air is close to ambient temp. inside in out. Once you get heat in it there's a lot more temperature differential and the draft will be much stronger. So if it draws in the steam even slowly in an unheated shack your probably good. I would try heating the shack up before testing. Your other choice is just hook it up and build a fire and see if she draws the smoke out. Either way an elbow or two isn't going to matter a lot in my opinion. I have a wood stove in my basement that is set up through the wall with two elbows and it draws like sucking on a straw.

[Pdiamond]

Whichever way you decide on make sure that you use double wall thru the wall/roof. You may have to check local fire codes to see what clearances are required thru the wall/roof. It may call for triple wall pipe. Just be extra cautious as you don't want a fire.

[therealtreehugger]

One of my big improvements when I redid my roof, from disintegrating shingles to a metal roof, was to go straight up through the roof, instead of out the window with two 90 deg bends, like it was. Why would you need a 90 deg if you went through the roof? Just go straight up. I had to move the evaporator over just a few inches so the double walled stack went in between the rafters.
Good luck!

[eustis22]

I need one 90 degree bend because, on the Mason, the exhaust hole is thru the back, not thru the top.

[therealtreehugger]

Ah. Makes sense. All other things being equal, the more your stack is vertical, the better. The more it is horizontal, not better. On one hand, every little bit helps. My rig has improved over the years due to many small adjustments. On the other hand, if you are only considering 2 ft of horizontal, how much difference are you really looking at? It may not matter.

[bigschuss]

I went out the wall first on my Mason 2x4 and have no issues whatsoever. I agree with the realtreehugger...probably will not really matter for a small operation. I would do whatever is easiest for you.