Enhanced Tubular Heat Exchanger

A heating, ventilation and/or air conditioning (HVAC) system, comprising:

• a heat exchanger, comprising:
• at least one heat exchanger tube, comprising:
• a first pass;
• a second pass;
• and
• a third pass;
• wherein at least a portion of the second pass and at least a portion of the third pass comprises an elliptical portion.

A method of operating a heating, ventilation, and/or air conditioning (HVAC) system, comprising:

• providing at least one heat exchanger tube in a heat exchanger of the HVAC system, the at least one heat exchanger tube comprising a first pass, a second pass, and a third pass, wherein at least a portion of the second pass and at least a portion of the third pass comprises an elliptical portion, and wherein each of the second pass and the third pass comprises a plurality of dimples;
• generating an airflow;
• contacting the at least one heat exchanger tube with the airflow;
• and
• promoting heat transfer between a fluid passing through an internal passage of the at least one heat exchanger tube and the airflow.