Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
This only applies to variable speed cooling towers sharing the same basin. If the the towers don't share the same basin the towers should be modeled as separate objects:
Combining the towers and using 0.1 for the minimum flow rate would be fine.
As long as the towers are sharing the same basin and are variable speed I don't imagine there would be any benefit either way. It's probable worth running a test in E+ comparing the two options.
Yes, MaximalCel control saves more energy because of the exact reason you mentioned - the power consumption of the fans depends upon the cube (or a little less) of the fan speed. MaximalCel saves energy under almost all operating conditions if a variable speed fan is used. Further energy savings can be found by floating the tower leaving water temperature control to maintain a constant cooling tower approach temperature.
