A
refrigerant condenser having multiple sections of straight tubes terminating in segmented headers, each subsequent section having an overall cross-sectional area less than an initial section with the overall cross section of the initial section large enough to substantially reduce vapor velocity thus reducing the
refrigerant pressure drop; the total cross-sectional area dimensioned to cause entrance vapor velocity, to be sufficient to establish an internal film
heat transfer coefficient greater than the external
heat transfer coefficient while limiting the
internal pressure drop for the
heat rejection intended.