Optimizing chilled-water plant control.

Author(s) : ZHOU G.

Type of article: Article


In typical commercial buildings, water-cooled chilled water plants use a significant amount of energy. They account for between 10% and 20% of the overall facilities usage and serve roughly one third of the commercial floor space. From literature and experience the annual average "wire-to-water" efficiency of these plants ranges from as low as 0.3 kW/ton (12 COP) up to 1.2 kW/ton (2.9 COP) or more. This efficiency is strongly influenced by three factors: the equipment efficiency (chillers, towers and pumps); the system configuration (e.g., the pumping scheme and types of control valves); and control sequences (e.g., equipment staging and setpoints). This article presents a parametric analysis technique to optimize the control sequences of chilled-water plants that has been successfully applied to dozens of project. This optimization technique is based on peer reviewed research and validated through measurement and verification techniques. Unfortunately, the techniques used are not presently available in standard off-the-shelf simulation tools.


  • Original title: Optimizing chilled-water plant control.
  • Record ID : 2007-2755
  • Languages: English
  • Source: ASHRAE Journal - vol. 49 - n. 6
  • Publication date: 2007/06


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