The peak flow being, for example, 100 USGPM, the HX is designed as such, with a 5F approach. However, the flow sometimes drops to a mere 15 USGPM, and must go through the same HX. It has been suggested that such a case will induced laminar flow, and that the heat exchange will not allow for a comparable temperature approach.

This being said, no one seems to be able to provide first hand experience nor documentation that would support this statement. We also thought that providing pumps that could increase pressure at the inlet might compensate and induce a turbulent flow, but we could not confirm this either (at this time, we cannot demonstrate experimentally).

Can anyone confirm that the low flow rate is indeed a problem under a 20% design flow rate and/or provide information about the effect of the low flow in the HX or the means to ensure a proper exchange if it is indeed a problematic situation?