Bengali Pit / Dakota Fire Hole with thermal mass chimney - will it work?

Hi,

We are wanting to heat a low portable tunnel house (5ft tall and 4 ft long). This is a short-term thing until we can afford a permanent walk-in Greenhouse. We are wondering how it would work to build one of these underground fires and run a chimney pipe from the top through the length of our green house. (We would have the chimney pipe in a wooden box of stones, sand etc. to heat during the day). It would be quick and easy, the hottest part of the fire would be well away from the Plastic - esp if the plastic blew down), we could put the feed tube outside the greenhouse, and it would be almost invisible.

Because we a few miles from the beach, and on sandy soil, I will probably have to line my hole somehow. I thought of having a 6" or 8" tube to feed the fire, and also that the hole/ heat riser itself could be either clay lined (and use clay to seal in the connections between the riser and the feeder tube and exhaust tube) or it could be made out of piled up bricks.

Any comments on how this will work? It should hot, but will it draw heat into the chimney?

Annie

http://civilwarlibrarian.blogspot.com/2008/05/news-archaeology-heating-military.html

It worked back then. You are replacing their Crimean oven with an in-ground J tube burner.

Funny, my task is also to heat the soil in a greenhouse over winter. Supposing that sunlight and collected heat wont be enough, especially over night? This ancient stove seems ideal, if we can make it work with the incomplete information that we have. My understanding for the workings of a rocket stove is that the vertical exhaust should be twice the horizontal run. Now if a good enough draft can be had with only eight feet or so of stovepipe then we are in business. Our greenhouse we are now building is 70 feet long. What I was thinking of doing is to have one or two of the 55 gallon barrel type rocket stoves inside the greenhouse, surrounding the barrels with some heat storage material like water or a water/stone mix to keep it warm overnight. But is this enough for the soil, I ask? If our ancestors' model could be replicated, that might be the best solution for our kind of folk. Thoughts?

"My understanding for the workings of a rocket stove is that the vertical exhaust should be twice the horizontal run. "

I am trying to work this one out. By vertical exhaust do you you mean the exhaust pipe up at the end needs to be twice the length of the piping running through the thermal mass? That seems far too much when i have read about thermal mass piping that runs 30-60ft long.

Annie