by Shane Henson — February 1, 2012—CALMAC, a leader in energy storage systems, recently completed the installation of its IceBank thermal energy storage tanks at the recently retrofitted Romeoville High School located near Chicago, Illinois. School district officials worked with Trane, a provider of indoor comfort systems and solutions and a brand of Ingersoll Rand, and Kenneth J. Kogut & Associates to design and oversee the installation of a partial energy storage system, resulting in a more efficient cooling system in the building and enhancing reliability, resiliency and redundancy.
Replacing the high school’s old 350-ton system, the new partial storage system includes 900 ton-hours of ice storage capacity and a 200-ton air-cooled chiller from Trane. According to CALMAC, improvements also include a Trane Tracer building automation system to optimize efficiency of chiller plant operation. To provide smarter, more efficient cooling for the high school, the building controls have the chiller charge the ice storage tanks, creating stored cooling, during off-peak hours when electricity costs could be much lower.
The IceBank thermal energy storage tanks are also a necessity when the Windy City isn’t so cold. During warm days, the controls use the chiller and the stored cooling energy to cool the school. When the weather is temperate, the building is cooled using only the less expensive stored energy from the tanks. The partial storage system—also known as a hybrid cooling system—combines the added feature of a thermal battery to a smaller conventional cooling system. This affordable energy storage feature provides redundancy and resiliency while reducing cooling costs.
“Everything has worked exactly as planned. CALMAC offers the reliability that we were looking for and the energy savings that we were hoping for,” said Christopher Thill, lead HVAC technician for schools in the Valley View School District, including Romeoville High School. “The Valley View School District has already seen remarkable benefits in terms of energy savings and system reliability. A great example of the reliability is when the chiller once went down due to a power blip and went unnoticed for quite some time. While the chiller started right back up once reset, our ice tanks allowed the whole situation to go completely undetected by the building occupants.”
