Reducing my draft tomorrow

[WellSeasoned]

I've posted this before, but tomorrow I am removing 1 section of class A . I am reducing my chimney height from 18' to 15'
I just have high flue temps even when the stove is aired down. Because I have 3' run of outside air (oak)(per code), right behind the stove, I feel the stove pulls air faster due to the restriction as opposed to room air, and it flushes fast into the stove. I know backwoods savage did it, if he would like to chime in with why he did it, and the results.

 

[bluedogz]

I've posted this before, but tomorrow I am removing 1 section of class A . I am reducing my chimney height from 18' to 15'
I just have high flue temps even when the stove is aired down. Because I have 3' run of outside air (oak)(per code), right behind the stove, I feel the stove pulls air faster due to the restriction as opposed to room air, and it flushes fast into the stove. I know backwoods savage did it, if he would like to chime in with why he did it, and the results.

Flashing back to college physics here... but if your OAK is pulling faster due to narrower aperture (relative to room air), the air coming through the OAK will flow faster, but not in greater volume. So, the reduction in chimney height may reduce draft pressure (if that's a term), thus causing less air to TRY to flow through the OAK.

That said, why &$#! with the class A at all? Why not just restrict the OAK intake to see if you get the same result?

 

[WellSeasoned]

Flashing back to college physics here... but if your OAK is pulling faster due to narrower aperture (relative to room air), the air coming through the OAK will flow faster, but not in greater volume. So, the reduction in chimney height may reduce draft pressure (if that's a term), thus causing less air to TRY to flow through the OAK.

That said, why &$#! with the class A at all? Why not just restrict the OAK intake to see if you get the same result?

That is an option as well. When I had the install, I made them throw on another section, even though they said it wont hurt, but wasn't needed.

 

[Todd]

How does you OAK run, is it above or below the stoves air intake?

 

[Backwoods Savage]

I've posted this before, but tomorrow I am removing 1 section of class A . I am reducing my chimney height from 18' to 15'
I just have high flue temps even when the stove is aired down. Because I have 3' run of outside air (oak)(per code), right behind the stove, I feel the stove pulls air faster due to the restriction as opposed to room air, and it flushes fast into the stove. I know backwoods savage did it, if he would like to chime in with why he did it, and the results.

I did it when putting up the new chimney. By putting on the height originally planned it could have posed a problem getting to the cap and I first checked the draft. Then removed some pipe and checked the draft again. I could not detect any difference. It should be noted that it was September when we put that new chimney up so draft was not expected to be too great. We were pleasantly surprised to find we had plenty. Still, I do not advise going shorter than recommended. We just lucked out.

From what you described, I doubt you would notice much difference in reducing the 3'. I'd advise leaving it as is.

 

[WellSeasoned]

How does you OAK run, is it above or below the stoves air intake?

Its pretty much dead even. In from outer wall even, slight sag a few inches, then few inches back up into stove.

 

[WellSeasoned]

I did it when putting up the new chimney. By putting on the height originally planned it could have posed a problem getting to the cap and I first checked the draft. Then removed some pipe and checked the draft again. I could not detect any difference. It should be noted that it was September when we put that new chimney up so draft was not expected to be too great. We were pleasantly surprised to find we had plenty. Still, I do not advise going shorter than recommended. We just lucked out.

From what you described, I doubt you would notice much difference in reducing the 3'. I'd advise leaving it as is.

BW- I hear ya, 3' maybe no difference. Maybe I'll research alittle more.