Hot air furnace with improved heat exchanger construction

摘要

A hot air furnace which includes at least one heat exchange unit having at least one mounting flange section defining an opening therein and a plate member having an aperture therein corresponding to at least one of the openings in said heat exchange unit and in alignment therewith with sheet insulating material interposed between said plate member and heat exchange unit by virtue of the said flange being expanded into a plane parallel to that of said plate member to thereby secure the plate member and interposed insulating material in place on said heat exchange unit.