two 45 degree elbows instead of a 90 degree?

Just got my NC30 wood stove. I am running it through a concrete block wall in my basement. Initially I planned on going straight up for about 3 ft to a 90 elbow, then continue for about 4 ft of Horizontal run (with a slight incline of course) and running eventually into the outside double insulated Stainless Steel Tee, and doing another 90 at the Tee to continue to the roof. The black stove pipe I am using inside the house is Selkirk DSP if that matters.
So heres my question. Wood I benefit significantly by using two 45 degree stove pipe elbows instead of the first 90 elbow I described. This would reduce the amount of horizontal run I have to about 2.5 to 3.0 ft. With this scenario most of the horizontal run would now consist mainly of double insulated stainless steel chimney.
Hopefully the combination of Double Insulated Pipe and DSP will keep things warm and improve draft.

thanks

fossil said:

Yeah, the installation pic in post #2 is NOT the OP's stove. A pic of the OP's stove would certainly help. In general, the more changes in direction, and the more abrupt those changes in the flue gas flow path, the more opportunity for the gasses to cool and the condensation/deposition of creosote. The increased complexity of the gas path also complicates effective cleaning. Two 45°s instead of a 90°, coupled with a shorter horizontal run is a good thing. Rick

Click to expand...

To answer, I am the guy that posted the thread, not the guy with the 30' tall chimney and the pic. Consequently my outside vertical chimney will be about 17 or 18 feet

Newguy777 said:

To answer, I am the guy that posted the thread, not the guy with the 30' tall chimney and the pic. Consequently my outside vertical chimney will be about 17 or 18 feet

Click to expand...

Here is a pic. Facing the wood stove, the chimney pipe would go up and out the left wall (The wall with the insulation in it). If I did use two 45s, technically I would come up 1 foot, go into a 45, go diagonally about 30 to 40 inches, go into the second 45, go about 6 inches horizontally and then continue horizontally with a 2 foot section of stainless steel double insulated pipe to the outside tee. From the tee, 17 feet to the roof.

dougand3 said:

2 x 45* elbows should draft better. And when you go through the wall - have a slight incline outward.

Click to expand...

Actually that leads me to another question. How can you put an incline on any section of horizontal pipe when you are tying into a 90 degree tee or for that matter coming off of a 90 degree elbow. Is there some flex room where the sections tie together?

dougand3 said:

You may not be able to incline IN the wall thimble - it may sit horizontally. The black stove pipe can incline from elbow to thimble. The black pipe will be cocked slightly downward in the thimble.

Click to expand...

Design wise, I thought the stainless steel double insulated pipe went from the Tee, through the wall, through the thimble and ended from 3 to 6 inches into the room, then transitions to black stove pipe. Is that wrong?

dougand3 said:

I don't know. Do you have a pic of yours or is it coming later?

Click to expand...

I posted the pic above. Its the one with the open walls

dougand3 said:

I meant a thimble/stainless pipe pic. But if black pipe travels only 6" from top elbow to the thimble - an incline won't matter. We're talking of only a 1/4" per foot of horizontal travel anyway.

Click to expand...

I looked at the thimble and it is made for a 8 inch (outside diameter) double insulated pipe. Because of the thickness of my block wall, studded interior wall, etc. I will be using a 24 inch section of stainless steel double insulated pipe. So technically I would have needed .5 inch of fall. Guess there isn't much I can do about this ?

RSNovi said:

Sorry. for the confusion. I was just trying to provide an example that works ok with 90s.

Click to expand...

No, its fine. I really appreciated everyone's help here. I am new to owning and installing wood stoves. There is so much to know! thanks again.