Patent ID: 6983788

Claim:
A heat exchanger comprising in combination, a plurality of panels of thermoplastic material having dispersed air-filled cavities, each of said panels having two opposed broad surfaces and at least one edge, each of said broad surfaces having a greater surface area than said edge, selected ones of said panels having at least one indentation in at least one of said broad surfaces, said indentation forming a gas flow passage cavity, others of said panels each having at least one gas flow conduit structure forming at least one gas flow conduit, said selected ones of said panels being interleaved with said others of said panels in a predetermined sequence, said panels being assembled with said broad surfaces of said panels joined together so that said gas flow passage cavity in each of said selected panels forms a gas flow passageway with one of said broad surfaces of an adjoining one of said other panels, said gas flow passageways in said selected panels and said gas flow conduits in said other panels are positioned to conduct gases in substantially opposite directions over a substantial portion of their lengths, said heat exchanger having a housing with at least one solid integral side wall formed by said edges of said panels being aligned with one another and fused together over a substantial portion of their lengths.