University chills: New water plant to begin operations

By Corydon Ireland

Harvard News Office

With sustainability and energy efficiency in mind, Harvard University will put in operation a new chilled water plant by January. The underground plant will be next to the Northwest Science Building now under construction at the north end of campus.

The new chillers will operate so efficiently that Harvard is getting a rebate check of $250,000 from NSTAR at a ceremony Tuesday (Dec. 18). The new hardware will also reduce chiller-related greenhouse gas emissions.

The chiller plant is fully operational, but does not officially begin operations until January. During its commissioning phase this year, NSTAR officials estimated how much more efficient the chillers would be, and, therefore, the amount of the rebate.

“The campus is growing” and with it a demand for chilled water, said Thomas Vautin, Harvard’s associate vice president for facilities and environmental services. But the new plant adds capacity while saving money and reducing Harvard’s environmental footprint, he said.

According to a release from Harvard’s University Operations Services, “The construction of the [new chillers] is a prime example of how Harvard engages in responsible expansion.”

The new plant includes three high-efficiency chillers, two heat exchangers, and eight cooling towers.

Chillers are precision machines designed to remove heat from a liquid by means of a refrigerant. The resulting chilled water, distributed through pipes, is then used to cool and dehumidify air in commercial-scale buildings.

At Harvard, the new chillers are the latest addition to a district cooling system that serves 73 campus buildings. In the new iteration of the system, two interconnected plants will generate chilled air, then distribute it in tandem.

The older chiller plant has been in operation at the Harvard Science Center for 35 years. Chiller machinery there takes up the center’s largest room, a chamber 40 feet deep on the building’s Oxford Street side.

Harvard also maintains several smaller chiller plants, most notably at the Harvard Business School.

Last year, Harvard’s Engineering and Utilities operation replaced two of the Science Center’s five 1970s-era chillers — “part of a greater effort to increase the efficiency and reliability of our cooling network,” said Michael D. Conner, spokesman for University Operations Services.

The demand being created by the new Northwest Science Building would have been too great for the Science Center chillers alone, he said.

The two chiller plants, across Oxford Street from one another, will comprise what’s called a district cooling network. That has advantages over what is called a distributed system, which locates cooling equipment (like window-mounted air conditioners) at individual facilities.

District cooling networks result in less noise, greater energy efficiency, increased reliability, better space efficiency, and simplified maintenance.

The Northwest Science Building — 210,000 square feet above ground and 260,000 square feet below ground — will be completed in February. It is visible from Oxford, Hammond, and Gorham streets.

In addition to the chiller plant, the new building will house an electrical substation, office space, classrooms, and collections. But it will primarily be used for open and flexible laboratory space that is designed to ease interdisciplinary research.

corydon_ireland@harvard.edu