Masonry wall adaptor and insulation or leave as is?

[rtrev37]

Hello, I am installing a new masonry double wall adaptor (for a wood stove) into my new 6 inch chimney liner that is also a double wall or smooth wall liner. As you can see from the pic, there is a 1" or so gap between the new chimney liner and the previous (larger) liner I had before. Once I place my new adaptor, the chimney liner will be suspended with a gap all around it from the adapter till the tee in the back.

Question: Does this gap need to be filled with insulation? should it be filled with insulation or can it be left as is? will insulating it make for a better draft due to the insulation and keeping that horizontal run warmer longer?

Objective: My first objective is safety. Second objective is to have a good draft since I could not insulate the entire liner due to the original clay limiting space availability to insulate the liner with the 1/2 insulation. The original clay was in good condition. My after thought was insulating the liner from the wall adapter inside the home all the way up to the tee.

What is your opinion? thank you for reading and commenting

 

[jerrieric]

I don't see any issues with a gap. Just think of a pellet stove wall thimble. There's a gap between the place you put the pipe in and the metal going around it. This keeps the high temperature away from the combustible material

 

[rtrev37]

I don't see any issues with a gap. Just think of a pellet stove wall thimble. There's a gap between the place you put the pipe in and the metal going around it. This keeps the high temperature away from the combustible material

it's a wood stove and posted in pellet stove section by mistake. However, I also thought it may be ok to leaving it as is while having the gap may act as double wall.

Yet, I still wondered if insulating it is recommended to improve draft due to it being a 30" horizontal run. inside I have an addition 10"-12" from the stove 90 degree elbow to the wall adapter which increases my horizontal run- which I did not want. But not sure if insulating such a small piece would make any difference.

I also thought of decreasing that interior horizontal run by placing a 6" connector oppose to the present 12" connector from the 90 elbow to the wall adapter. This would bring my stove closer to the wall and be less than the 10" wall clearance recommended by the manufacturer when using double wall. I asked the manufacturer if that would be ok with a full brick wall with no combustibles behind it but they refuses to ok that set up. Maybe this should be another thread...