Abstract: Method of combusting hydrocarbon fuel to form combustion products low in nitrogen dioxide (NO2) and carbon monoxide (CO) and mixing the combustion products with additional air to provide a heated air stream suitable for heating enclosed spaces includes the following steps: (a) delivering a fuel stream to a burner assembly; (b) delivering a combustion air stream to the burner assembly; (c) combining the fuel and air streams within a combustion chamber and heat exchanger wherein the mixture is ignited, completely combusted, and the temperature of the products of combustion are reduced; (d) providing tempering air to the external side of the combustion chamber and heat exchanger to transfer heat away from the combustion gases to tempering air; (e) combining the partially heated tempering air and cooled combustion products low in NO2 and CO; and (f) discharging the mixture into a space to be heated.

Abstract: Method of combusting hydrocarbon fuel to form combustion products low in nitrogen dioxide (NO2) and carbon monoxide (CO) and mixing the combustion products with additional air to provide a heated air stream suitable for heating enclosed spaces includes the following steps: (a) delivering a fuel stream to a burner assembly; (b) delivering a combustion air stream to the burner assembly; (c) combining the fuel and air streams within a combustion chamber and heat exchanger wherein the mixture is ignited, completely combusted, and the temperature of the products of combustion are reduced; (d) providing tempering air to the external side of the combustion chamber and heat exchanger to transfer heat away from the combustion gases to tempering air; (e) combining the partially heated tempering air and cooled combustion products low in NO2 and CO; and (f) discharging the mixture into a space to be heated.

Abstract: A fuel burning device includes a tubular combustion cylinder open at opposing first and second ends. A fuel inlet pipe has a first end extending through the first end of the combustion cylinder partially into the combustion cylinder and a second end extending outside of the combustion cylinder. The fuel burning device also includes a burner head connected to the first end of the fuel inlet pipe and an orifice connected between the burner head and the first end of the fuel inlet pipe. The burner head is structured and arranged so that combusted fuel discharged at the second end of said combustion cylinder has reduced CO and NOx emissions.