Abstract: This heating apparatus includes an air flow chamber having outer and inner, generally cylindrical and parallel walls within which a combustion chamber is nested. The combustion chamber includes means for burning a fuel and has outer and inner parallel, generally cylindrical heat conducting walls. It is coupled to an exhaust duct which has at least a portion thereof surrounded by the inner wall of the air flow chamber. In one form air is driven by an electric fan through the air flow chamber around the combustion chamber and out to a distribution duct. The fan also blows air into the combustion chamber for combustion of the fuel. In another form, a fan is driven by th combustion exhaust gases thereby propelling air through the air flow chamber and into the combustion chamber via a compressor wheel. Other forms include heat-conductive members placed into contact with the exhaust duct or with the air chamber to further heat the air before it enters the distribution duct.