ITHACA, N.Y. -- Cornell University's Lake Source Cooling project has entered the pilot-testing phase and is operating at about 25 percent of its full capacity to cool central campus facilities by utilizing the naturally cold water of Cayuga Lake.

During the test phase, the new system is producing 5,000 tons (60 million Btu/hour) of cooling -- approximately one-third of the campus' needs on a warm summer day-- and an increase to 16,000 tons of cooling is expected within a month. The system of heat exchangers, pumps and underground water lines is designed for a full capacity of 20,000 tons of air conditioning and process cooling for buildings on the university campus and the Ithaca High School.

Construction for the $60-million system began in March 1999, and a formal dedication is planned for later this year. Monitoring of environmental conditions in the lake began before construction and will continue as long as Lake Source Cooling is in operation, in accordance with permits that were granted to build and operate the system.

Lake Source Cooling draws water at 40 degrees F from 250 feet below the surface of Cayuga Lake through heat exchangers on the shore, where some of the lake water's chill is transferred to campus water that is piped -- in a closed loop -- from the university two miles away. The heat exchangers ensure that water in the two loops will never mix. Cooled campus water is distributed to laboratories and other buildings, while lake water leaving the heat exchanger is returned at 47-56 degrees F. The cold, deep water of Cayuga Lake is regarded as a renewable resource because warmth added to the lake -- the equivalent of four hours of sunlight a year -- is released to the atmosphere each winter.

The new system replaces conventional mechanical chillers that use CFC (chlorofluorocarbon) refrigerants, and Lake Source Cooling is expected to reduce the university's consumption of fossil-fuel-based electricity for cooling by 80 percent. The annual savings of 15 million kilowatt-hours of electricity (enough for 2,000 typical homes annually) will reduce emission of greenhouse gases in regional power plants, avoiding production of 55 million pounds of carbon dioxide per year.

More information on Lake Source Cooling is available at the Cornell utilities department web site: http://www.utilities.cornell.edu/lsc/.