Class A double-wall chimney pipe for heat riser and burn tunnel?

Hi folks,
First post, so I'll try to be clear and concise.

I see a lot of used Class A double-wall refractory insulated stainless chimney pipe in our local Craigslist. (Many are replacing wood stoves with pellet stoves.) Much of it is in 3' or 4' sections, and it connects easily with airtight connections. Some of it is reasonably priced, and I have some leftover parts from a recent soapstone wood stove installation.

I would like to create a "snap together" RMH using off the shelf parts. Could this type of product be used to simplify assembly of a portable rocket mass stove, specifically the heat riser and burn tunnel? There are tees, 45s and 90s available in Class A chimney that could be used for the burn tunnel and feed tube, and the Class A pieces are far more robust than the black stove pipe often used for the burn tunnel and feed tube. The lid of the barrel could be used to mount the Class A 3' or 4' pipe in the same fashion as through the wall Class A chimney mounts permit a connection under the wall tee support:


For the heat exchange barrel exhaust flue, would it be possible to use the two stove pipe collars in the Vogelzang double barrel adapter kit?


In other words, use two standard flue adapters on the bottom edge of the heat exchange barrel. Then run two 6" stove pipes in parallel through the heat storage mass area for 6 to 8 feet, connect them with a tee at the far end, and then connect to flue to outside?

I have no idea how to calculate the areas/diameters necessary to make these work, but off the shelf parts are preferable to me versus scrounging/fabricating and trying to get airtight assemblies with refractory brick and adobe or cob.

Any thoughts?

Thanks in advance,
Brian in PA

" insulated stainless chimney pipe in our local Craigslist"

No responses? I just came on looking for an answer to the same question!

It will work for a while. About as long as it will survive a chimney fire. It might work for a cooker or a prototype.

You need to make sure it is the good stuff, 100% stainless, not the stuff with SS liner and galvanized outer layers. Or else you will create a whole lot of DEADLY off gassing in a hurry.