ASHRAE 90.1 addresses efficiency for chilled water pumping systems with guidelines for controls that result in pump motor demand of no more than 30% of design wattage at 50% of design flow. The concept of differential pressure control is an essential part of variable speed pump control to maximize efficiency, highlighted in ASHRAE 90.1.
There Is No One-Size-Fits-All Control Strategy in Variable Speed Pumping
Sensored and sensorless control are among the options to satisfy ASHRAE 90.1
February 21, 2020