Capital University, Columbus, Ohio, faced a problem. With a tight budget and two 33-year-old chillers that needed replacing, the school needed to look at various options. The situation was made worse when the absorption chillers failed in the cooling season. The school temporarily rented chiller capacity to get through the cooling season, but it was evident that long-term action was needed.
The university purchased a system with two 1,000-ton centrifugal chillers and an 800 hp natural gas engine-generator set from The Trane Company. The Gas Powered CenTraVac chiller package can run on either electricity or gas.
"We needed a system that would meet our own needs for the next 20 to 25 years," says Frederick McKinney, superintendent of buildings and grounds.
A window in the mechanical room allows observation of the engine and its gauges. Two cooling towers on the plant building roof serve to cool condenser cooling water and engine jacket water.
The new system can bring the chilled-water system to its operating temperature, 44oF, within 20 minutes, says Rex Fisk, energy and control specialist. The older system would take hours. Present load levels allow the entire campus to be cooled, even on the warmest days, with one chiller.
The university chose to use a hospital-grade muffler to deal with the acoustics, because of the chiller's proximity to Capital's Conservatory of Music. So far, there have been no complaints about the noise, says McKinney.