30 degree elbow in chimney?

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lumbajac

Member
Hearth Supporter
Mar 15, 2008
85
Upper Peninsula, Michigan
Hello - looking to install an RSF Opel2 with ICC chimney in new home construction. I will burn 24/7 for a good 6 to 7 months utilizing the optional central heating kit to duct heat from the fireplace into my natural gas forced air ductwork for whole house heating. Due to the placement of the fireplace I will need to put a 30 degree elbow in the chimeny once in the attic, run straight for a bout 12 feet, then another 30 degree elbow to return to vertical, then another 3 feet or so of straight pipe and out near the peak of the house. Would need to do this in order to position fireplace in the optimum place within the house (and the only place that will really work) yet still get chimney to exit near the peak of the house. My rough calculations suggest I will need approximately 30 feet of pipe to do this.

If I went with a straight shot up from the fireplace the chimney would rise out of the roof less than half-way up from the eave of the roof. The roof is at a 10/12 pitch, so to meet code I would need the chimeny to rise above the surface of the roof from its exit point a good 9 feet or so. This is okay according to code and I've seen this quite a bit so nothing unusual about it. My only concern is that aesthetically it might not look the best given the chimney is on the street side of the home and the second conern is that we may have 12+ inches of snow on the roof at any given time so I don't like the idea of that much height sticking out of the roof with a potentially heavy load of snow pushing and pulling down of the chimney at roof level. I am quite sure the chimeny could handle the snow no problem with some roof ties for additional stablization, but part of me is still concerned about such a setup.

The chimney would be running through two stories of heated home in a chase then entering the cold attic space of the roof trusses... this is where the two 30 degree bends would reroute the chimeny to the peak of the house. The concern I have with the 30 degree bends, especially being that they are in the cold part of the house structure, is that you are somewhat changing the physics of the smoke flow while at the same time cooling the smoke. I have concerns that this arrangement will encourage creosote buildup (although this should be very, very limited due to the unit being clean burning and according to the fireplace manufacturers literature). At the same time I think its better to get the chimney and smoke to exit near the peak of the house if possible. My thoughts also are that if such elbows meet code, they comply with the manufacturers instructions, the manufacture allows up to 4 elbows in a chimeny and I'm only looking to use 2, and the chimney company itself sells elbows that it must be okay.

Any thoughts on this potential setup - good or bad?

Thanks,
lumbajac
 
As long as the setup meets the guidelines in the install manual it will be fine. We put 30 deg elbows in the attic all the time to hit the chase when its not centered right over the unit.
 
Just ensure that you support the pipe according to the manufacturer's installation instructions and you will be fine.

P.S. Just because your stove is "clean burning" doesn't mean there will be no/little creosote buildup. Most creosote buildup is due to poor burning practices and not stove design.
 
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