Indiana State University

Chilled Water Study and Design

Rendering provided by RATIO Architects

Applied Engineering was retained by Indiana State University (ISU) to analyze their existing chilled water system. The chiller plant was nearly at capacity, and the campus planned on adding new buildings. The plant had a capacity of 4,540 tons and was able to thermally store cool air at night through a bank of ice storage tanks (16,000 ton-hours available). However, ISU had not used the ice storing capability for several years, so the system was analyzed to determine its long-range effectiveness. The study concluded that ice storage was no longer an effective means of maintaining cooling on campus. New locations were investigated to identify a site for a new chiller plant on the west side of the campus to service the additional loads. All findings, calculations, observations, conclusions, and recommendations were summarized in a bound report. This study was completed in January 2005.

In 2007, the Applied team consisting of Applied, RATIO Architects and Ter Horst, Lamson & Fisk, Inc. (the civil and structural engineer) was retained by ISU to design the new satellite chilled water plant recommended in the study. From the time when the study was completed, new campus buildings were under construction (including a new student recreation center) and changes had occurred in plant construction. Therefore, fundamental changes in the schematic design of the project were needed. It became clear that the chiller plant location identified in the study would not be compatible with the close proximity of the new student recreation center. New locations for the plant site were examined and the northwest corner of campus was deemed to be the location of the new plant site. A chiller size increase from 1,250-ton increments to 2,500-ton increments was executed to increase the capacity of the first stage installation and to meet the fixed construction budget.

The satellite chiller plant is designed to be operated from a remote location using the campus system control network. It is designed to be powered through the campus electrical 12 kV system using dual redundant circuits. A set of 24” PVC chilled water mains will connect to the campus chilled water system, and the main plant will operate in unison with the new satellite plant. Variable frequency drive chiller drives were recommended to improve plant efficiency at lower loads.

The project design was completed during the summer of 2009 and is ready for bidding. The project budget is $7,072,000. This cost includes power connections, distribution piping and design fees. Construction is slated to begin in 2010.