If heat transfer is enabled, the number of thermal sections that are used to calculate heat transfer in Pipes and Heat Exchangers can be modified in the Heat Transfer Sectioning panel, shown in Figure 1.

Because the amount of heat transfer is dependent on the temperature difference at any given point, an overall average would not give an accurate estimate. Sectioning heat transfer components increases the accuracy of the calculation due to the changing thermal profile. Very large thermal changes may require additional sections.