[craigepo]

You know, if I were going to install that heater in a building where I was going to be sleeping, I would probably spend a little more money than what was shown on the heaters in the videos.

We don't have any building codes here, and folks used to line their chimneys with ceramic flues. Ceramic worked fine for a while, but once you have a creosote buildup, which starts an unknown flue fire, the ceramic can crack, which can later result in a house fire. So, insurance companies started making everyone line their chimneys with stainless steel.

I wonder if you could find stainless steel flue material to use inside that thing, then put your cement/stone/whatever substance on top of the steel?

Also, regarding running the exhaust out of the house, if you are installing the heater into a wood frame home, you want some temperature barrier between the flue and the wall/roof. I have a pellet stove in my present farm house, and they are so efficient they only need 3-inch flue material, with a pre-fab fitting holding the flue in place in the wall. I wonder how these folks are setting up their chimneys...