Variable flow chilled water or how I learned to love my VFD

Variable flow chilled water systems have been a bone of contention among HVAC engineers for many years. Many still believe that they can't and don't work, or that the flow through the chiller cannot vary, or that they shouldn't be balanced, or can't be balanced, or whatever. Well, after having designed and commissioned and watched many variable flow chilled water systems operate successfully, the author has a few insights that are worth hearing-and heeding.