Abstract: A stove and method for burning solid fuels having an insulated primary combustion chamber, uniform distribution of preheated primary air through upward facing holes in a grate, downward flow of combustion gas through the grate, retention of hot coals in the grate structure, preheated secondary air, individually controlled primary and secondary air flows, insulated vortex combustion chambers for secondary combustion, longitudinally finned tubes as a first stage heat exchanger, plate-fin assembly as a second stage heat exchanger, an induced draft fan to draw the air and combustion gases through the combustion chambers as well as the heat exchangers, and a forced air fan to blow cool room air through the two stage heat exchanger.

Abstract: An improved grate and method for burning solid fuel having a support for the fuel, a fan, a multiplicity of preheated air jets uniformly distributed across the entire area of the grate and directed through the support generally upwardly into the lower burning surface of the solid fuel, and a trough for collecting a layer of glowing coals located immediately below the jets and in close proximity to the burning lower surface of the solid fuel. The grate provides the cleanest burning and lowest fuel consumption occurs when only one layer of solid fuel is placed on the grate.