Chimney - Sloped or below peak?

New house, putting an Osburn Horizon in great room, 8" DuraTech flue, not centered in house EW although pretty close NS. High sloped roof with 8:12 pitch on a ~3 story house. The entire roof is insulated with R70+ so the conditioned space is everything under it. Top floor is not fully conditioned, but for this exercise we will assume it is. This means that if I don't slope the flue, then I would have about 8' of pipe sticking out above the penetration point of the roof to meet the 10:3:2 rule, or I can put a long slope in the flue and penetrate near the peak. Looking for some advice, would I be better to penetrate with a straight run and maybe incur stack affect, as well as a long external flue on the roof (which I can frame around), or to slope it and have issues with cleaning and lower draft. Image included of South elevation with sloped chimney.

I don't think the lowered draft incurred by the slope would be too bad because of the overall height so I'm 'leaning' towards the sloped solution.

Looking forward to the help!!

 

Welcome makulais! You've come to the right place!

Calling brenndatomu Well Seasoned double-d

 

The clean and inspect was my concern also, but straight up puts me 7'8" under the peak and needing an 8'+ flue sticking out of the roof. It also makes my penetration 8' lower than the highest heated space in the house. Not too worried about the cost differential, that's minor to the rest of the build and I figure my wife would make me build an external chase around it anyway, that cost would eclipse the extra flue from going up at an angle. I would assume there are clean out joints I can put in?

 

With a sloped flue, would I just want to put a tee and cap in at the top of the sloped section and another at the bottom? Does this make the clean and inspect issue go away?

 

Okay so one way or the other, cleaning it can be done, I'm surprised they don't make the angles with a clean-out port where it would be more like a Wye? The plug could actually be formed to make a smooth interior wall pretty easily so it wouldn't screw with the draft. That would seem to be the best way in my mind (engineer here!).

 

Decided to go with the straight flue, got some local advice from a few chimney sweeps, they didn't think I would have any issues with the stack effect and therefore the vertical would be the way to go.

Next step, deciding on the chimney manufacturer. SBI, the manufacturer of the Osburn Horizon, makes a chimney called NEXvent? I cannot find any information on it, not sell sheets, catalogs, technical sheets, installation manuals, nothing. Anybody ever heard of it? I'm kind of wary of using something that is so unknown and probably difficult to find. Would probably rather go with either DuraVent or S2100+ because of that but if someone else knows something about the NEXvent, I would appreciate the feedback.

 

Welcome aboard makulais

I used Duravent for my chimney, as it was easily sourced locally.

Looking forward to seeing the pics of the stove.

 

That's pretty much my view also. Not very confident in purchasing something I can't find on the internet from a different source. What got me is the local dealer refused to quote it? I voiced my concerns and he said this is what Osburn/SBI makes and recommends, even though the manual states about 10 different manufacturers pipes as being good with it. What a PITA. So I'll probably just go with on online retailer rather than the local. Surprised a dealer would refuse to do that, oh well, his loss.

 

I would go straight up , and not be concerned with the Stack effect, and you don't have to mess with the 30 deg elbows. I use the Ventis Double Wall Class A pipe, both Selkirk and DuraVent are good also.