Abstract: A firebox for burning solid fuels which avoids common problems causing pollution and poor efficiency, by methods to ensure that the firebox is hot, to provide hot combustion air, to exploit radiant heat effects, by focusing surfaces, by burning heated secondary air on the face of a reactor. The reactor also serves to meter secondary air to suit fire size. The firebox per se is not a complete stove; it requires the addition of a heat exchanger which may be to air or hydronic, integral or remote, and which in turn is amenable to variations in design.

Abstract: This invention relates to method and apparatus used as an addition to any existing heating system--burning any fuel--for heat recovery from stacks and chimneys. It uses a suitable heat exchanger mounted at the apex of such stacks, by virtue of which location no natural draft is lost. The system includes a circulating pump, a thermostat, an expansion bottle, a condensate trough, a cap and dome which jointly serve to act as unloaders to protect the system liquid from being boiled off. Both sensible heat and the latent heats of moisture in the fuel and in the vapor produced as a combustion product, can be scrubbed out. The use is to effect economies and to reduce environmental contamination wherever fuels are fired.