You won't find this setup at the local stove shop! While inspecting a cabin in western Maine for a home inspection client one recent summer, this is the heating system we encountered. The cabin was owned by a Russian immigrant who was an engineer, so I call this a "Russian flue". I thought it was kind of a neat idea but the new owner's insurance company thought otherwise. They made her remove it, probably because of the number of twists and turns involved, as well as the increased surface area for creasote to cool out and accumulate, either in the flue or in the chimney.