University of Vermont

University Communications

UVM Formally Dedicates $14 Million Centralized Chiller Plant

Release Date: 07-26-2007

Author: Enrique Corredera
Phone: 802/656-2005 Fax: (802) 656-3203

Green AC may seem like a contradiction in terms. But that’s just what the University of Vermont’s new $14 million Central Chiller Plant, the only facility of its kind in Vermont, comes closer than most to delivering.

The efficient new plant, the first phase of a $19 million upgrade of the central utility infrastructure on main campus, is expected to save the university hundreds of thousands of dollars in energy and operating costs. Located in the Central Heating Plant, the facility began operating in May and was formally dedicated at a ceremony on the UVM campus on July 26.

“Many large buildings at UVM are now occupied year-round, and warmer summers are further increasing the demand for air conditioning,” said Daniel Mark Fogel, UVM president. “With the new Davis Student Center coming online, the time had come to upgrade the campus cooling system to a new level of efficiency, reliability and environmental friendliness.”

Initially, the central chiller plant will serve the Bailey Howe Library, Royall Tyler Theater, the Old Mill/Lafayette complex, and the Davis Center. In the future, the university will expand the plant’s coverage to include the Given Medical Building, the Health Science Research Facility, and a new science research building the university plans to complete within the next few years, pending trustee approval.

From dirty to clean
The central plant pumps chilled water through a system of underground pipes to and from buildings. It replaces local, electricity-powered air conditioning systems in Bailey Howe, Royall Tyler, and Old Mill/Lafayette.

Because air conditioning systems operate most frequently during periods of peak electric demand when supply is stretched thin, the electricity serving them often comes from the least environmentally friendly systems, including diesel-fired generators.

The new system is powered by campus steam generated by the heating plant’s boilers, which are fueled with cleaner burning natural gas. Two tractor-trailer sized chillers housed inside the plant create the cool water.

Chillers traditionally run on large electric motors. UVM opted for an advanced steam-driven technology to take advantage of the existing infrastructure of the Central Heating Plant. “The new chillers allow us to put more load on the university’s boilers, which supply heat to the campus in winter, during the non-heating season, which makes them more efficient and reduces their operating and maintenance costs,” said Salvatore Chiarelli, director of UVM’s Physical Plant.

Similar systems have recently been installed at the University of Maryland’s Comcast Center, the College of New Jersey, several New York metropolitan hospitals and Providence Hospital in Washington, D.C.

Green coolants to variable pumps
The chiller plant, a joint project of UVM’s Physical Plant and its department of Facilities Design and Construction, boasts a variety of green features in addition to its fuel.

According to Michelle Smith Mullarkey, UVM’s green building coordinator, the chillers use an environmentally friendly and relatively new coolant called HFC-134a, a hydrofluorocarbon with an ozone depletion potential of zero. The selection of the new chilled water plant’s refrigerants is contributing LEED green building credits to the Davis Student Center.

Burlington Electric Department played an important role in enhancing the plant’s energy efficiency. While centralized heating and air conditioning plants are more efficient distribution systems, they can still use electricity unnecessarily.

“The electrical efficiency at the plant is enhanced dramatically by including variable speed electrical drives for the large pump and fan motors,” said Jake Yanulavich, BED project engineer. “When the chiller plant is running at a fraction of its full capacity, these drives allow the plant to ramp down appropriately, resulting in a high level of energy efficiency.”

Because of these and other efficiency investments, UVM received a $38,000 rebate from BED and Efficiency Vermont, designed to offset higher up front costs. The plant’s more efficient pumps, motors, lights and transformers will reduce its annual operating costs by $68,000.

The partnership between UVM and BED to reduce electricity use began in 1988 and has resulted in millions of dollars in avoided costs, earning a Governor’s Award for Environmental Excellence in 2006.