I have seen a commercially available stove that has a double-skinned surface, the air comes in and is pre-heated in the labyrinth, which adds to the combustion process. Cannot remember the name, but it is a good little stove. Sticks and any small tinder make a good hot cooker!
"ROGUE ELECTRICIAN" Hoping to be around to re-energize the New World.....
Cogito, ergo armatus sum