Guideline 22-2012 -- Instrumentation for Monitoring Central Chilled-Water Plant Efficiency
Guideline 22 was developed by ASHRAE to provide a source of information on the instrumentation and collection of data needed for monitoring the efficiency of an electric-motor-driven central chilled-water plant. A minimum level of instrumentation quality is established to ensure that the calculated results of chilled-water plant efficiency are reasonable. Several levels of instrumentation are developed so that the user of this guideline can select that level that suits the needs of each installation.The basic purpose served by this guideline is to enable the user to continuously monitor chilled-water plant efficiency in order to aid in the operation and improvement of that particular chilled-water plant, not to establish a level of efficiency for all chilled-water plants. Therefore, the effort here is to improve individual plant efficiencies and not to establish an absolute efficiency that would serve as a minimum standard for all chilled-water plants.Guideline 22-2012 includes a Web link to a supplemental Excel spreadsheet with an example of the effects of energy use, Delta T, and variable flow for both COP and kW/ton calculations.Keywords: Chillers, evaporator pumps, condenser pumps, cooling towers, chilled-water Citation: ASHRAE Guideline