Jefferson Community College

Challenge

The James McVean College Center, one of Jefferson Community College’s eight permanent buildings, houses offices, space for music instruction, a dance studio, dining facilities, a fitness center, the 478-seat Sturtz Theater, and a large multipurpose gymnasium, used for athletics and other events, such as the college’s graduation ceremonies. While a perfect venue for a variety of college activities, the aging McVean Center was in need of serious renovation. Originally built without air conditioning, a combination of direct expansion split systems and window air-conditioning units had been installed in portions of the building over many years. The college wanted to centralize cooling to improve efficiency and increase comfort for its students, faculty and guests, all on a limited budget.

Solution

Jefferson Community College consulted with its engineer regarding the needed upgrades. While the college wished to increase its cooling capacity by more than fifty tons, adding electrical capacity would require a substantial, and costly, utility upgrade that could jeopardize project approval. One way to add cooling without extra power: increase system efficiency. In addition, the engineer did not want to place an undue burden on a reduced facility staff. A water-cooled system would require water treatment and additional equipment to be maintained, while an air-cooled system might not be efficient enough. The engineer suggested a chilled-water plant with ice storage and requested competitive bids.

Trane proposed the EarthWise™ Ice-Enhanced Air-Cooled Chiller Plant. Based on previous experience with Trane, both the college and the engineer knew they could rely on Trane as a single source for professional consultation, systems and services. The engineer was also thrilled with the simplicity of the system design. Trane was selected to partner with the college and the engineer on the upgrade.

A simple, highly efficient, quiet design

With a pre-engineered standard system configuration, integrated with a system controller and operator interface, the Trane EarthWise™ Ice-Enhanced Air-Cooled Chiller Plant simplifies the design and implementation of a system typically considered complicated. A 90-ton CGAM air-cooled scroll chiller, supplemented by four CALMAC IceBank® thermal energy storage tanks and a Trane system completion module, serve the desired 200-ton peak cooling capacity, with increased comfort and a better learning environment.

Managing peak demand

The EarthWise Ice-Enhanced Air-Cooled Chiller Plant builds ice at night during off-peak hours when the building cooling and power load is low. Shifting the time when cooling is created allows the college to take advantage of lower-cost, off-peak electricity, as well as milder outdoor conditions for improved system  efficiency. During the day, the ice and the chiller work together to cool the facility. The ice tanks and the downsized chiller help the college manage peak electrical demand and avoid a costly substation upgrade.

Optimizing performance

Building operators use a Tracer™ SC controller to manage the EarthWise System. With a click of a button, facility managers can monitor equipment, make set-point changes, manage alarms and decide whether to melt, make or preserve ice. Tracer SC dashboard screens make reporting and programming adjustments simple, at a workstation or with remote access via devices such as smartphones or tablets. The campus uses Tracer ES™ software to integrate the variety of control systems currently in use at the college and help them make enterprise-wide decisions.

Results

A Trane EarthWise Ice-Enhanced Air-Cooled Chiller Plant has allowed the Jefferson Community College to nearly double its cooling capacity while decreasing utility costs. The efficient system provides the college with load shifting flexibility to help manage peak demand, avoid a costly electrical substation upgrade, and take advantage of lower cost off-peak electricity. Comfort has been enhanced, and with the chillers working mainly at night and further away from occupants, sound levels have been reduced.

“We haven’t fully tested the chillers to see what kind of loads they can handle. In most instances so far, we have been able to use ice-only to cool the facility,” said Bruce Alexander, Director of Facilities, Jefferson Community College. “We want any renovation we do to be as ’green’ as possible. The EarthWise system is aligned with our green initiatives.”

“Overall our utility bills have gone down," said Dan Dupee, Vice President for Administration and Finance, Jefferson Community College. “Trane has been very responsive and great to work with.”