Adam Smith

I was wondering about this myself. It would be very hard to get an insurance company to approve it since it's not UL listed. And there is no way to regulate or shut off the burn; no air intake regulator or damper downstream. And the barrel heat chamber would be prone to rusting out in a few years and would need a way to be changed out quickly and efficiently without having to chiesel it out. And the flue. They are going to want to see a clay tile lined flue, espeically if it is over wood. And I don't know about it running sideways without any or hardly any rise. I know from experience on a regular flue they want triple wall stainless steel or the clay liners inside the flue that funnel the flue gases into the next joint so that if the mortar cracks or falls out the flue gases will still be contained. I would think the thermal mass would develop cracks over time or you would have to at least expect it to. I don't know how long the galavanized 6" stove pipe will last encased in the thermal mass, but not permanately. From our King circulator heater to the flue we would change out the blued pipe every few years.

Franklin, we have a 30x70 greenhouse where I work and it has an outdoor furnace that uses wood. We made the furnace from a piece of pipe (just like a barrel stove) then surronded that with a rectangular box made from plate metal. We have a blower from a central air conditioner unit that blows air from inside the greenhouse, into the rectangular box and around the stove, and back into the greenhouse into a clear plastic tube 18" in diameter, with small holes on both sides, that hangs from the ceiling the length of the greenhouse. It can be bought from a greenhouse supplier. The far end of the tube is tied shut like a trash sack so warm air comes out the small side holes. The trick to heating it though is that we have two layers of plastic over the greenhouse with a small centrifugal fan blowing air between the layers to keep them seperated. The air space is insulation. You can tell a world of difference. In 20 degree weather you will be in a t-shirt and it is warm from one end to the other.