Seems to me after much study and little practice that there's a common principle that can be used here in a survival situation.

I've dug a couple Dakota holes, with unremarkable results. Wet soil sucks the heat out of a Dakota hole fire. But as I consider how I had seen a Dakota hole is supposed to be, I think maybe the idea of a rocket stove might make more sense in the future.

The idea of getting the fire to draft such that combustion is more complete (less smoke, more heat) has me reconsidering the way I will try and build the next Dakota hole fire. I think next time I will dig into a mound, or mound up my dirt around the chimney hole, and cut my draft hole at an angle, and so the opening is below the top of the chimney as much as possible, but within reason. It might take it a bit to get the burn chamber idea working in cold soil. But I bet once you get it drafting well, you should be able to build up quite a bit of cleaner heat.

Hmm, all this studying is giving me all sorts of ideas. I got a stovetec sitting in the garage and haven't tried it yet. Maybe I should consider playing around with that thing for a while. I wonder what happens if you make the chimney output hole longer. I bet it will improve combustion, up to a point that is.

It seems there are really two versions of rocket stoves. Those like my little stovetech, which are really just primary burn chambers with a horizontal feed, and a more robust design with something like a refractory chamber where the combustion gases get superheated and result in a more complete combustion. The little ones tend to make a lot more soot. Whereas the ones with the chamber tend to burn quite clean, produce more btus per fuel consumed, but are not altogether as portable.

I don't play with fire near enough these days. I used to be quite the pyro back in the day, but working at a desk has dimmed the spark a bit.