Facility Focus

Facility Focus: Ohio University Chilled Water Plant #3

• By Matt Jones
• 05/01/22

Ohio University in Athens, Ohio, recently completed construction on a third chilled water plant for its campus. The appropriately named Chilled Water Plant #3 (CWP3) measures in at about 23,000 square feet and stands three stories tall. Like the campus’ two existing plants—West Green Chilled Water Plant and Nelson Chilled Water Plant—it’s a mechanical building that provides chilled water to the campus loop for use in everything from academic research to air conditioning.

The steel-framed chiller plant is wrapped in insulated metal panels and storefront glazing, and it features an auger cast pile foundation system. Most importantly, the equipment inside includes chillers, pumps, controls, mechanical piping and an electrical substation that ties into the campus’ existing distribution system. It provides an additional 7,500 tons of chilled water capacity to the campus, while its design addresses environmental and sustainability issues like flooding and noise pollution.

"They provide chilled water, which supports research and daily life with air conditioning," said Jane Weinzapfel, Principal with Leers Weinzapfel Associates, which designed the project. "That's their largest purpose. And by serving a campus or large urban district, the equipment can be larger, more efficient, and more easily maintained because it was purchased at the same time. It's a large benefit for campuses in their growing sustainability efforts to reduce energy—both energy cost and energy use—in a way that will be environmentally better.”

Building mechanical facilities to house this type of equipment is usually preferable to installing it on top of a building, Weinzapfel explained. Rooftop machinery can’t be as easily maintained; different structures built at different times may use different types of equipment; and they introduce needless noise into crowded parts of campus.

There are certain design elements to be mindful of when building a mechanical facility as opposed to an academic building or residence hall. Chief among them is the equipment’s need for annual maintenance. "Service and access—both to the building and within the building—are critical for maintaining the function of the systems and for the installation and removal of large equipment,” Weinzapfel said. “That vehicular service to the outside of the building, so that you can add equipment or remove and install new equipment, is of key importance to these buildings.”

Chilled Water Plant #3 features three bifold glass doors that allow large access into and out of the building. This large access comes in handy during the machinery’s annual cleaning, which requires equipment almost as long as the chiller plant machinery itself. Maintenance crews can open the double doors and use the outside as maintenance staging and access. The bifold doors also allow for future installations of large equipment.

The project narrative on the Leers Weinzapfel Associates website explains that the main equipment floor raises about nine feet above ground level, providing ventilation for the main floor. Ramps also provide vehicles access to that main floor. The building’s interior is wrapped in an acoustical sound wall with a screened enclosure at its top, offering noise protection to the surrounding area.

Of the university’s existing chilled water plants (West Green Chilled Water Plant and Nelson Chilled Water Plant), West Green is a standalone water plant, and Nelson is located inside a residence hall. Nelson hasn’t run for a couple of years because of aging and unreliable equipment, but it could be used during peak conditions if needed, said Vince Jarret at RMF Engineering. The ultimate goal is for CWP3, once fully built out, to replace the Nelson Plant entirely. Either West Green or CWP3 alone can provide chilled water to the entire campus during low-demand periods, but both are needed during the warmer months, said Weinzapfel.

“The ideal situation is that they’re on a loop,” she said. “But they do, in general, serve a more nearby area through piping underground, which is called distribution piping. But it’s ideal to hook the piping in a loop configuration so that, for resiliency, they offer a kind of a backup on the larger system.”

While the first two plants were built in central, utility-heavy locations, the third one stands removed on the South Green, near campus intramural fields. It was built to support campus growth and provide additional chilled water generation capacity for areas that may see development in the coming years.

“This third plant was because of campus growth, with the need for additional chilled water generation capacity,” said Weinzapfel. “And there was no room for expansion at either of their other two plants…This one is near some recreational fields of the university’s, and other areas the university owns and may be developing in that direction—physical direction—
of campus.”

At the end of the day, Weinzapfel stressed that these types of structures are particularly important in an era when people are concerned about resiliency. “People don’t want to be without their power or their air-conditioning or what have you; it can be a grave concern,” she said.

But beyond reliability, chilled water plants serving large groups of people offer a degree of fuel efficiency and air quality that can’t be matched on a small scale. The district-cooling approach that many campuses are taking serves to meet larger sustainability goals, both explicit and common sense.

“Because they can use high-efficiency equipment, they can use more than one fuel, so they can be prepared to transfer to innovative fuels as they come forward,” Weinzapfel said. “And because they’re more efficient, they’re just better for everyone’s air quality, as well. Rather than, say, the other extreme of window air conditioners or something…the universities have the opportunity to do this in a district-wide way, which is very important for those larger goals that universities have.”

This article originally appeared in the Spring 2022 issue of Spaces4Learning.