Flattened tube finned heat exchanger and fabrication method

A heat exchanger for transferring heat between a first fluid and a second fluid comprising:

• at least a first heat exchanger slab and a second heat exchanger slab;
• the first heat exchanger slab including a first manifold, a second manifold spaced from the first manifold, and a first tube bank extending between the first manifold and the second manifold and including a plurality of tube segments extending longitudinally in spaced relationship, each tube segment defining an internal flow passage for the first fluid;
• the second heat exchanger slab including a first manifold, a second manifold spaced from the first manifold, and a second tube bank extending between the first manifold and the second manifold and including a plurality of tube segments extending longitudinally in spaced relationship, each tube segment defining an internal flow passage for the first fluid, said second heat exchanger slab being disposed in generally parallel alignment with said first heat exchanger slab, the first manifold of said first heat exchanger slab and the first manifold of said second heat exchanger slab juxtaposed in spaced relationship at a first side of said heat exchanger, and the second manifold of said second heat exchanger slab and the second manifold of said first heat exchanger slab at a second side of said heat exchanger;
• and
• a plurality of folded fins disposed in a flow path of the second fluid through said heat exchanger and in operative association with the plurality of tube segments of the first tube bank and the second tube bank, each fold fin having a depth extending at least from a leading edge of the tube segments of the first tube bank to a trailing edge of the tube segments of the second tube bank;
• wherein a centerline of the first manifold of said first heat exchanger slab is offset from a centerline of the first tube bank by a first non-zero offset distance and a centerline of the second manifold of said first heat exchanger slab is offset from the centerline of the first tube bank by a second non-zero offset distance, the first non-zero offset distance and the second non-zero offset distance being unequal.