Indeed, in the prototype of the brickstove we build at Hans Baarslags's workshop (see preheating). The setup of this prototype was too rough and too leaky, also the tiles we used cracked immediately when heated. But the idea is clear: air could stream in under a thin stainless steel divider in a horizontal channel. Above this stainless steel sheet metal, the hot gas would stream out the fire box, in our design that is the place under the container where the wood could slowly sink and burn into the fire. Heat exchange between cold inflowing air and hot outflowing gas should be the result.