Abstract: A heat exchanger apparatus includes an inlet header, an inlet connection connected to the inlet header, an outlet header, an outlet connection connected to the outlet header and a plurality of serpentine tube bodies. The plurality of serpentine tube bodies interconnect and are in communication with the inlet header and outlet header. Each serpentine tube body has a plurality of straight tube sections and a plurality of U-shaped return bend sections. Each one of the straight tube sections and each one of the return bend sections have an elliptically-shaped cross-sectional configuration. The plurality of serpentine tube bodies are arranged in a juxtaposed manner with consecutive ones of the serpentine tube bodies contacting each other at a point defining a series of stacked common planes disposed parallel with one another.

Abstract: A heat exchanger tube includes a tube body forming a hollow passageway and having a U-shaped tube section defining a return bend, a pair of straight tube sections and a pair of transition sections. Respective ones of the straight tube sections are connected to the return section with respective ones of the transition sections disposed therebetween. The straight tube sections extend generally parallel to one another. Each straight tube section has a straight tube cross-sectional width and the return bend has a return bend cross-sectional width that is smaller than the straight tube cross-sectional width. Multiple heat exchanger tubes can be connected together to form a serpentine heat exchanger tube. Multiple serpentine heat exchanger tubes or multiple heat exchanger tubes can be assembled together to form a heat exchanger apparatus.