chimney height

[OrpingtonManor]

Hello. I am new to this forum. I have heated exclusively with a pellet insert since 2005, but just purchased a Morso 1410 Squirrel. The installation document that came with the stove recommends a minimum chimney height of 16 feet. I am planning to run the flue out the back of the stove, through a combustible wall (will need a wall thimble to allow for proper clearances, I know), make a 90 degree turn, then on a 45 degree angle for 2 feet, then another 45 degree angle to be completely vertical up to, and through the soffit and roof. From the point at which the stove pipe will reach vertical, it is 8 feet to the high side of the roof penetration. I understand the 3foot-2foot-10foot rule. My roof has a low pitch. The chimney pipe will penetrate the roof about 2 feet from the peak. I know I need to be at least 2 feet above the peak, but that is a moot point because adding 3 feet above the roof will be higher than that. All in all, the chimney will only be about 12 feet above the stove using those calculations. Would you add the extra 4 feet? I believe it would mean bracing the chimney because it would be more than 5 feet above the roof line. Thanks for giving me any insight you have.

 

[DAKSY]

I would add the 4 feet & maybe more.
Each offset will effectively decrease your chimney height.
Speaking of offsets, if you're planning on using 45 degree
offsets for your Class A chimney, you'd better think again - YOU CAN'T.
The max offset for a Class A chimney in the US is 30 degrees.

 

[OrpingtonManor]

I will be able to make it work using a 30 degree offset. Thanks for letting me know that.

If I add the 4 feet, I will be 7 feet above the roof, which is very low pitched. At what point does it become a larger problem with bracing against wind?

 

[LLigetfa]

Bracing required at 5 feet.

 

[annette]

I have the additional roof bracing for my chimney, since I too have a low-pitched roof. Definitely don't go shorter, with all those bends. Plus you live in a climate where most/all of your burning will be at "warmer" burning weather, (30s-40s) where you need better draft.

 

[OrpingtonManor]

It sounds like I will need to put the chimney 7 feet above the roof, and brace it at 5 feet. I didn't realize the draft would be less because of my "warm" climate. I know that an exterior stovepipe/chimney cools more quickly than one that runs internally, but hoped that my climate would make things better because the flue gases wouldn't cool as quickly as one built in the north. Keep talking to me. I'm learning with every post! Thanks!