In 1994, the exportation and importation of Chlorofluorocarbons (CFCs) were banned in the United States due to their active role in the depletion of the ozone atmospheric layer. Chlorofluorocarbon is a compound of carbon, hydrogen, chlorine, and fluorine and is typically found in certain refrigerants. Cornell University, along with millions of other corporations around the country, was faced with the dilemma of handling their existing CFC chillers and how to sustain the increase in cooling demand in the near future. Cornell had two options: to reinstate newer, ozone-friendly chillers or tackle a risky choice—capturing the cold from the bottom of Cayuga Lake and somehow transporting it to, through, and around the Cornell campus. Through this system, which has come to be known as Lake Source Cooling, Cornell has instituted a sustainable, environmentally sound innovation that shines a light on a brighter future for our university and the planet.
Lake Source Cooling (LSC) is the process through which the natural chill produced at the base of Cayuga Lake is utilized for the cooling of Cornell and parts of the IHS campus in the warm months. 39 degree Fahrenheit water ten feet off the bottom of the lake, nearly two miles below the surface, is pumped up towards heat exchangers in the LSC plant off Lake Shore Drive in Ithaca. These heat exchangers separate the two plumbing loops that make up the process. By the time the water has reached the heat exchangers, the temperature has increased by a few degrees, although it remains cool. Another plumbing loop can be found on the other side of the heat exchangers. This one is a closed-campus loop that pumps chilled water around campus, gradually absorbing heat out of the air. Eventually, the water goes back toward the heat exchangers, now close to 60 degrees Fahrenheit, which transfer the heat out of the warmed water, chilling it once again with the natural chill produced by the lake water in the plumbing loop on the opposite side of the heat exchangers. The chilled water then returns to campus to repeat the process. Meanwhile, an open lake-water loop, which works like a vacuum, pulls cold water from the depths and then pushes this same water back out to the shallow waters of the lake, unchanged, besides the fact that it is a bit colder and clearer than surface water.
This technological advancement has been attempted in multiple other places around the world, including Honolulu, Sweden, Switzerland, Nova Scotia, and even nearby Toronto. This efficient, low-maintenance system of utilizing the chill produced by a renewable resource will bring about many benefits, such as being cost-efficient for its long life expectancy, energy savings, sufficient cooling method, and replacement of attested unsustainable CFC chillers.
With a reliable seventy-five to one hundred estimated usage years, LSC could last almost two times as long as the old CFC chillers, according to Cornell’s Facilities and Campus Services. Cole Tucker, director of utilities distribution and energy management for Cornell Facilities and Campus Services, explained that “Lake Source Cooling, at its core, is about six times more efficient than any traditional chilled water plant.” Tucker added that four million gallons of water and 50,000 dollars in electricity costs are saved annually. The projects’ construction phase alone totaled two million dollars in value toward taxpayers of ICSD and the City and Town of Ithaca.
In the planning and construction of the project, the impact on the lake was brought into consideration. So much consideration, in fact, that it resulted in a four-volume, 1500-page Environmental Impact Statement that went in-depth on the possible environmental impacts. It guided the project to carry out a conscientious construction that had minimal impact and a dutiful monitoring program, collecting data and verifying safe operation.
In return for granting LSC property for the system, IHS will receive cooling from the lake in the same manner. The LSC plant is open for public tours so those interested can learn about how the system works and its environmental impacts.