HVAC for Educational Testing Service Expansion
As part of a large expansion
The primary equipment includes two ~827-kW (235-ton) rotary screw chillers (Series R(r) CenTraVac(r) Helical-Rotary Chillers), two~196-kW (20-hp) primary chilled/glycol solution pumps, two ~392-kW (40-hp) secondary chilled/glycol solution pumps, two ~196-kW (20-hp) condenser water pumps, 16 ice storage tanks, and one double-cell, induced-draft cooling tower. The ice storage systems is designed to supply 20% of the kWh needed on a design cooling day. The ice is produced during off-peak periods when electricity rates are their lowest.
By using thermal energy storage, ETS was able to downsize the chillers for the system by 15%, further cutting energy consumption. Because the new office areas are not individually metered, it is impossible to provide precise energy savings data. However, a very rough estimate is 3,000,000 kWh annually.
The 315,000 ft2 (29,264 m2) expansion of office space on the ETS campus took the form of two new buildings. Without individual metering of the buildings, it is not possible to have precise data on energy savings. However, considering that there is a $9.72(USD)/kW/month on-peak demand charge but no intermediate or off-peak demand charges, it is apparent that using the thermal energy storage system to produce ice during off-peak hours significantly reduces what would otherwise be the energy costs. A system analysis estimates that simple payback for the project is about 3.1 years.
Educational Testing Service
The Trane Company
Michael J. Pawelski
608 787 4644 (Fax)
The Hillier Group