Patent ID: 7677238

Claim:
A heater for circulating heated air to an enclosed space, said heater comprising: a blower housing including an outer wall and opposed sidewalls; a rotatable impeller disposed within said blower housing for circulating air through said blower housing from at least one air inlet opening along an airflow path to at least one air discharge opening in said blower housing; and plural heat exchange conduits for carrying combustion gasses each comprising a first tube section for receiving the combustion gasses and a gas discharge tube section for discharging the combustion gasses, said plural heat exchange conduits disposed within said blower housing and disposed around at least a portion of the periphery of said impeller for heating air circulated by said impeller within said blower housing, wherein at least one heat exchange conduit of the plural heat exchange conduits comprises a heat exchange tube having a generally elliptical cross section; wherein at least one of the gas discharge tube sections is disposed substantially adjacent to the at least one air discharge opening in said blower housing and is located downstream along said airflow path relative to at least one of the first tube sections.