Indirect heat exchanger having circuit tubes with varying dimensions

An improved indirect heat exchanger including a plurality of coil circuits, with each coil circuit comprised of an indirect heat exchange section tube run or plate. Each tube run or plate has at least one change in its geometric shape or may have a progressive change in its geometric shape proceeding from the inlet to the outlet of the circuit. The change in geometric shape along the circuit length allows simultaneously balancing of the external airflow, internal heat transfer coefficients, internal fluid side pressure drop, cross sectional area and heat transfer surface area to optimize heat transfer.