Case Histories (Real-World Solutions)

Chiller Plant Optimization Saves Energy

chiller plant

The Institute for Bioscience and Biotechnology Research on the University of Maryland campus cut energy use an average of 30 percent by optimizing its chiller plant.

When the University of Maryland committed to reducing its energy consumption 20 percent by 2020, James Johnson, director of facilities and lab services, had to find a way to make the 110,000-square-foot Institute for Bioscience and Biotechnology Research (IBBR) more efficient.

The biggest target was the facility’s environmental stabilization plant, “as big an energy pig as there was out there,” says Johnson. The plant was only five years old and had few operational issues, but a consultation with Optimum Energy engineers revealed that optimizing each piece of HVAC equipment individually, as part of the whole system, could increase efficiency considerably.

Johnson also wanted to improve reliability and redundancy. IBBR connects top scientists in interrelated fields to perform world-class bioscience and biotechnology research that leads to real-world advances, and anything that stabilizes lab environments furthers the mission. Plus, Johnson had to ensure the facility’s two 450-ton, variable-speed electric centrifugal water chillers — which provide 3,800 hours of cooling annually — would work at optimal levels regardless of outside conditions, from icy winters to steamy summers.

To accomplish these goals, IBBR converted to an all-variable flow plant, with Optimum Energy’s OptiCx™ Platform as the optimization and control layer. OptimumLOOP ™ software calculates the most efficient operation of the chilled water system and optimizes plant performance in real time, dynamically adapting to changes in load, weather and occupancy to yield the lowest possible kW/ton while maintaining the optimal temperature.

In the first year, output almost doubled — yet IBBR cut energy use by an average of 30 percent.

“Prior to optimizing, in 2014, the plant baseline was about 0.9 kW/ton. By the end of 2015, it was 0.57–0.65 kW/ton,” Johnson says. “I’ve got a plant that is running at absolute maximum efficiency.”

This article originally appeared in the issue of .