Cool Customers

Cornell’s Natural Air Conditioning Plan–And Its Critics

You can’t see the 42-inch, high-density plastic pipes from the top of Cornell University’s McGraw Tower, but they’re there, snaking up Ithaca’s trademark gorges to “the campus on the hill.” Filled with water drawn from the icy depths of Cayuga Lake, the pipes make Cornell’s experimental air conditioning initiative, Lake Source Cooling, or LSC, possible.

Anyone who has ever discovered an open window in winter knows that heat flows naturally toward cooler areas. The $60 million LSC system is based entirely on this principle. After being sucked up from the eternally frigid reservoir at the bottom of Cayuga Lake, water is pumped to a heat exchange facility, where the lake pipes meet and wrap around a second set from a closed loop that serves the Cornell campus. Elementary transfer of heat occurs between the two sets of pipes without traditional CFC refrigeration or the energy that produces it. The newly chilled water is then pumped up the hill to air-condition the campus and the now tepid lake water is dumped back into a shallow discharge zone at Cayuga Lake’s southern shore.

According to the university’s official LSC website, the project “saves enough fossil-fuel energy to power a fifth of all the households in the City of Ithaca (roughly 2,000 homes), reduces local air pollution from power generation, speeds the elimination of ozone-depleting refrigerants, and provides unprecedented insight into the ecology of Cayuga Lake.”

But critics—many of whom learned their biology at Cornell—remain unconvinced. Although limnologists have steadfastly maintained that LSC has “no discernable impact” on Cayuga Lake and is equivalent to only four to five hours of sunlight a year, many residents feel betrayed that the university is using their lake as a guinea pig for the world’s first inland lake cooling project.

And their concerns might be valid. Four weeks after LSC went online, rhizoclonium, a previously undocumented algae in the lake, bloomed in an area roughly the size of a football field near the discharge zone. “I don’t know why the rhizoclonium has suddenly appeared,” says Rich DePaolo, spokesperson for the Cayuga Lake Defense Fund (CLDF), “but the only thing that’s changed in the lake for the past 30 years is the introduction of LSC.”

But Lanny Joyce, Cornell’s senior mechanical engineer in charge of LSC, dismisses the critics’ concerns. “It’s too bad the CLDF doesn’t recognize the science behind the project,” he argues. “The group is creating all these doomsday scenarios that are completely unfounded.”