Patent ID: 7497247

Claim:
A heat exchanger comprising, in combination, a plurality of panels of thermoplastic material, each of said panels having two opposed broad surfaces and two opposed edges, each of said broad surfaces having a greater surface area than either of said edges, said panels each having a plurality of parallel gas flow conduits, extending in a first direction, and having two ends, spacers secured between said panels, said spacers forming at least portions of gas flow passageways between said panels, said spacers and panels together forming a heat exchanging core having two opposed ends and four sides, a housing enclosing said four sides while leaving said ends open to conduct gas into and out of said flow conduits, said housing comprising first and second pairs of plastic walls, each covering one of said sides and being sealed at its edges to the adjacent walls, at least one of said second pair of walls comprising melted material of said edges of said panels, said second pair of walls having a pair of spaced-apart openings, each opening exposing said edges of said panels adjacent but spaced inwardly from one of said ends, and said walls being selectively extended outwardly from said core to form extending ducts at said openings to convey gas into and out of said gas flow passageways between said panels.