single or double wall?

[agz124]

I am just about finished with the installation of my Quad 4300 step. The last thing I need is stove pipe and I am debating which to go with. Here is the set up:

I installed a flexible ss liner (21 feet) in my existing masonry chimney. I did not insulate it because both of the stove shops I spoke with said I should be just fine without it. If anything just insulate around the top foot of the liner with fiberglass (which I have not done yet). The liner comes down the flue 20 feet and then through the side of the flue, through the brick and that is where it will connect to a 90 and then a straight piece of stove pipe 23 inches long.

Should I buy a double wall 90 and straight or single? Insulating more than the top foot of the liner is not an option (at least for a while).

As always, thanks for the your help!

 

[stoveguy2esw]

i would figure double wall only if there is a "close clearance " issue , that short a run right off the stove is not going to cool your exhaust all that much, you would probably not even notice a difference performance wise, 18 inch minimum to combustibles with single wall , if you need to be tighter than that go with the double wall

 

[agz124]

I forgot to mention that I am 40 inches away from combustibles!

 

[stoveguy2esw]

GOLDEN in that case whichever you want to go with. ensure that you have a slight 1/4" to the foot rise in it if horizontal

 

[Gooserider]

If you are far enough from combustibles that clearance isn't an issue, there is no real advantage to the double wall with a short run.

I would try to insulate the top of the liner as best you can, but DON'T use fiberglass - it isn't listed for that application, and might not withstand the heat of normal operation, let alone a chimney fire. Use "Rock Wool" or Kaowool high temp stuff instead.

Also do you have a blockoff plate to prevent air leaking into the chimney from whatever used to be connected to it?

Gooserider

 

[elkimmeg]

Forget the fiberglass and when you find money shop the internet for ceramic insulation The fiber glass will suck in moisture and emitt cresote smell all summer long and not rated for that heat range

I agree there is no need for doublewall connector pipe But let me offer up anothe possible solution.

There are two types of single wall connector pipe

the common 24 gauge snap seam black smoke pipe cheapest way to go or

22 gauge welded seam black pipe It will last a lot longer no seam leaks all elbows and fixed position,
but is costs more, not as much at double wall, but a bit more than 24 gauge

Naturally ss steel is another option but cost even more and ill last more than 20 years

BTW that shop fiberglass recommendation in theory sounds right, but wrong material, bad advice.