Patent ID: 6889757

Claim:
A core structure of an integral heat-exchanger, comprising: at least two first heat exchanger tubes which extend in parallel with each other; at least two second heat exchanger tubes which extend in parallel with each other, wherein the two second heat exchanger tubes are juxtaposed with the first heat exchanger tubes; and a corrugated fin including a corrugated first part interposed between said first heat exchanger tubes, a corrugated second part interposed between said second heat exchanger tubes, and a flat connection part arranged between the corrugated first and second parts, wherein said corrugated first part of the fin is formed with a plurality of first louvers each extending substantially between the two first heat exchanger tubes, wherein said corrugated second part of the fin is formed with a plurality of second louvers each extending substantially between the two second heat exchanger tubes, wherein an innermost one of said second louvers is positioned away from an innermost end of said corrugated second part of the fin by a given length, wherein said flat connection part is formed with a third louver positioned closer to an innermost one of said first louvers than to the innermost one of said second louvers, wherein said third louver is constructed to obstruct a heat transfer in the fin, and wherein said third louver is positioned substantially across the width of said flat connection part.