Abstract: A self-starting, fuel-fired, air heating system including a vapor generator, a turbine, and a condenser connected in a closed circuit such that the vapor output from the vapor generator is conducted to the turbine and then to the condenser where it is condensed for return to the vapor generator. The turbine drives an air blower which passes air over the condenser for cooling the condenser. Also, a condensate pump is driven by the turbine. The disclosure is particularly concerned with the provision of heat exchanger and circuitry for cooling the condensed fluid output from the pump prior to its return to the vapor generator.

Abstract: A damper assembly for association with the draft hood of a fuel fired heating appliance to control flow of exhaust gases through both the flue tube and the vent pipe. The assembly comprises a pair of damper members shaped to conform to the cross-section of the inlets and outlets of the draft hood. The damper members are spaced apart a distance equal to the distance between the inlet and outlet and carried from a single mounting shaft which extends transversely into the draft hood generally midway between the inlet and outlet openings. Suitable power means are provided to rotate the damper members from a first position in which they are in alignment with the inlet and outlet openings to a second position wherein they are out of alignment and permit free flow of exhaust gases.