University of Oregon unveils upgraded cooling system

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A new, $37 million chiller plant at the University of Oregon is projected to cut energy consumption for cooling the university’s buildings in half. And while the measure of the plant’s efficiency – a target of .5 kilowatts per ton of refrigeration – is becoming standard in new cooling systems for campuses, this special design, created to fit an existing distribution system, may have benefits in other campus settings where building a new system isn’t a viable option.

The University of Oregon’s chiller plant is located in its own building on the 295-acre campus. It produces cold water using groups of chillers and cooling towers – much like giant refrigerators in a home – that pump the water through underground pipes to the campus’ more than 60 buildings. The building’s individual heating and cooling systems use the water to produce cold air, for instance by blowing fans over chilled water coils.

University officials decided to replace the chiller plant because the system’s energy use was inefficient. Built in several stages since the early 1950s with the last stage in 1997, the system was consuming energy at a rate of more than 1 kilowatt per ton of refrigeration, a costly problem. The chiller plant was also frequently in need of repairs, and finding parts for the old equipment proved tricky.

“We have a very strong commitment to sustainability and what we were after when we needed a new chiller plant was the most efficient facility that we could possibly get,” said Joe Mosley, spokesman for the university.

The cooling system also had to meet state specifications on energy consumption set by statute. But because the pipes are located underground in an established distribution network of tunnels, and the system is tied to buildings with individual heating and cooling systems already in place, university officials aimed to gain new efficiencies at the plant alone.

Wood Harbinger, Inc., a consulting engineering firm from Bellevue, Wash., was tasked with designing a system that could reduce the university’s energy consumption without replacing equipment in other buildings.

According to Jim Jenkins, vice president and director of quality assurance at Wood Harbinger, Inc., the firm’s approach was to coordinate the chilled water system components inside the plant, reducing energy consumption by forcing component manufacturers to work together.

Chiller plants typically involve chillers and cooling towers that come from separate manufacturers, creating a hodge-podge approach to construction. While the setup is common with many chiller plants, it can be inefficient. Jenkins said engineers in this case required the manufacturer of the chilling system to recommend a cooling tower, demonstrate its efficiency, and manage power requirements between the two, creating a central control system that maximized energy efficiency.

“This is probably one of the most unique West Coast installations to provide this system in this manner,” said Jenkins. “It would appear to us that our system, as we planned it, and after review against other nationwide campus results, compares very favorably with systems that are implemented as new or ‘greenfield’ projects today. They might have a different look to them but they have comparable values.”

The new chiller plant is projected to use half the energy the old plant once consumed. The project also qualified for an $870,000 energy-efficiency rebate from the Eugene Water & Electric Board, which provides cash incentives for projects that curb power demands.

Jenkins said the techniques and coordination used at the University of Oregon could also benefit other campus style energy distribution systems, in particular those that have developed over time and include assets that make a complete overhaul costly and difficult. He suggests eco-districts may also benefit, allowing some to offer chilled water distribution in addition to steam and hot water.

Lee van der Voo, lvdvoo*at*gmail.com, is a freelance writer for Sustainable Business Oregon.