Hey Ed, when measuring dry bulb ΔT, is adding volume to the equation a better indication of system performance?

In this edition of “Hey Ed,” Ed discusses measuring dry bulb ΔT and system performance.

Hey Ed, when measuring dry bulb ΔT is adding volume to the equation a better indication of system performance? - Whenever we measure a delta T, the system CFM or the volume of air moving across the system is very relevant. One of the magic numbers we shoot for at times is a 20 degree delta T across that coil. Well, if we have air flow in that magic 400 CFM per ton range, that’s a fairly good metric to determine if the sensible capacity of that system is appropriate. But if we’re running at 250 or 300 CFM per ton, there is an example where the performance of that system is less than ideal. Therefore, if we’re ever gonna do any kind of a temperature difference measurement, we should know the volume of the air. And that’s the way I see it.