Chillers operate more efficiently when they provide chilled water at warmer temperatures. A familiar EMS controls application keeps close tabs on the building load by measuring the return fluid temperature and rate of flow, then increases the supply temperature to match this load. The EMS acts in a limited, supervisory capacity. The chiller’s integral controls start the unit and otherwise control the chiller operation, while the EMS instructs the chiller to provide the required temperature of chilled water.
In combination with chiller sequencing, this operation enhances the efficiency of the chillers on-line by a delicate balance of load to chilled- water capacity.
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Excerpt from Energy Conservation Projects.