Does stack bends/draft matter when using a blower?

[TrentonMaple]

I'm wrapping up the construction of my new sugarhouse and it's time to install the stack. Having just roofed it and spent a ton of money and effort on a metal roof, I am a little hesitant of cutting a hole in my roof to run the stack straight out. This would also require me to cut the ridge beam as well directly behind the cupola. The flashing of the stack also concerns me, as roof peak flashings or jacks are hard to come by.

I am considering either running the stack straight out back from the evaporator, through the back wall, then up the back of the sugarhouse, or making some 45 degree turns to angle it up and through the top part of the back wall.

I know bends in the stack reduce draft. I know the height of the stack is important to the draft. But is draft a consideration when using a blower? I run a squirrel cage blower on my Mason 2x4.

[COMSTOCK MAPLES]

I did the same thing. metal roof and ridge. Mine has two 45's in it. Haven't ran it yet but I believe on 8" stack it will be fine, I'm running a little higher than last year to compensate. When I had a wood stove in my house it had to 90 degree elbows and I had to damper it alot to slow it back. Good luck to you

[morningstarfarm]

With a blower it wint make much if any difference...had 2 90's in my 2x6 stack with a blower and it worked fine for years

[bowhunter]

Bends do affect draft, but you should be fine. You can always extend the height of the stack if draft were to become a problem.

[BreezyHill]

The blower is just like adding a turbo to a motor you will get more air thru the system and the effects of an elbow of 90 is slightly amplified in a negative correlation; but the power of the blower will still over come these negatives provided the stack is not to long and creates to much back pressure On a natural draft, longer, to a point, aids the draft.

On my 2x6 I have 2 45 elbows and 14' of stack. When I added an additional 2' to get it furthered from the building there was a noticeable change in the burn and the extension was removed, but I piggy backed a second blower two seasons ago to get more cfm in the fire box to get a better burn and efficiency.

Ben

[Biz]

On my old leader half pint with homemade arch made from a 55-gallon drum, I had three 90-degree elbows and 5 sections of 3 ft pipe, no blower, damper, or working draft control (draws through front door), and I could get flames shooting out the top of the stack when loading with a few dry sticks of pine:) I figured the flame was about 18-20 ft long.

Dave