Allowed clearance VS possible clearance

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Rob_Red

Feeling the Heat
Feb 2, 2021
325
Southern New England
My ventis chimney manual states my wall pass through must “pass 6 inches into the room”, then I need to install a 90 degree elbow of stove pipe to connect the stove, so I’m guessing it’s pretty much physically impossible to have a stove connected sitting less than 12 inches from the wall.

Meanwhile my double wall stove pipe has a 6 inch required clearance to the wall and my stove manual states the stove can be 7 inches from the wall with double wall pipe.

What gives??? How do I enjoy the benefits of double wall pipes having closer clearances if I cant even physically hook the stove up that close?

Did I just discover a disadvantage of a through the wall thimble setup?

Maybe I should pass up on the advantages of the double wall and go with single wall and cut my 90 degree elbow down as close as possible?
 

Ctwoodtick

Minister of Fire
Jun 5, 2015
1,613
Southeast CT
As I’ve found with my pellet stove, I’m glad I chose to put it a couple more inches from wall than required. Accessing the back of stove would have been a real pain.
 
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kennyp2339

Minister of Fire
Feb 16, 2014
6,277
07462
I think 6" class A going into the room with a 6" dvl elbow puts you right at 12" then depending on the stoves rear clearance and flue collar location determines how far back the stove can sit in relation to the chimney connection.
I made the switch from single wall to double wall pipe years ago, and I have to say that the double wall is so much better made, stainless steel and lasts, I suppose single wall welded seam is hearty stuff but the other snap single wall is junk and I will never use that again.
 
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stoveliker

Minister of Fire
Nov 17, 2019
2,813
Long Island NY
Double wall pipe has closer clearances as measured in the radial direction. That has nothing to do with how close your stove can be to the wall.
 

Rob_Red

Feeling the Heat
Feb 2, 2021
325
Southern New England
Double wall pipe has closer clearances as measured in the radial direction. That has nothing to do with how close your stove can be to the wall.

What is the difference? I know the stove it’s self has a minimum clearance in my case it’s 7’. So to me this means If I didn’t go through the wall and went straight up through the house (eliminating the need for an elbow or my thimble sticking into the room 6’) I would be able to run the stove 7 inches from the wall and the pipe 6 inches from combustibles. However Since I’m going through the wall I will need to space out 12’
 

stoveliker

Minister of Fire
Nov 17, 2019
2,813
Long Island NY
What do you mean? I know the stove it’s self has a minimum clearance in my case it’s 7’. So to me this means If I didn’t go through the wall and went straight up through the house (eliminating the need for an elbow or my thimble sticking into the room 6’) I would be able to run the stove 7 inches from the wall and the pipe 6 inches from combustibles. However Since I’m going through the wall I will need to space out 12’

You equated using double wall pipe to the ability to move your stove closer to the wall. Double wall pipe has nothing to do with that (when looking at a thru the wall set up).

Now it turns out you ar comparing wall closeness for a straight up and out set up and a thru the wall set up.

None of this has to do with the specs of double wall pipe.
 

kennyp2339

Minister of Fire
Feb 16, 2014
6,277
07462
What is the difference? I know the stove it’s self has a minimum clearance in my case it’s 7’. So to me this means If I didn’t go through the wall and went straight up through the house (eliminating the need for an elbow or my thimble sticking into the room 6’) I would be able to run the stove 7 inches from the wall and the pipe 6 inches from combustibles. However Since I’m going through the wall I will need to space out 12’
Right, but in hindsight you might like the stove further away, nothing is more nerve racking then an accidental 800 deg stove stop from leaving the air open to long with smaller splits ripping, knowing that you exceeded the clearances from the manufacturer provides much peace of mind at times.
 
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