URBANA — In an ongoing effort to reduce greenhouse-gas emissions, the University of Illinois is installing a novel geothermal heating and cooling system within the foundation of a building addition going up on its engineering campus.
Instead of drilling separate holes for a system of geothermal pipes bringing up water heated or cooled under the earth, the project will embed geothermal heat exchanger loops in the foundation of a new "smart" pedestrian bridge that will connect the Hydrosystems Laboratory addition to the Newmark Civil Engineering Laboratory across West Main Street.
By using the 50-foot-deep shafts already being drilled for the foundation, the project will reduce overall geothermal installation costs and provide for on-site research, officials said. It will also heat and cool the new instructional geotechnical laboratory in the building for Tugce Baser, assistant professor of civil and environmental engineering.
The new installation approach, which costs about $240,000, is 30 to 40 percent cheaper than drilling holes for a more traditional geothermal "field" system, said Mohamed Attalla, director of UI Facilities and Services.
"It's a fairly new technology. The university will be the first in the nation to have this kind of research going on in our work here," said Attalla, who worked with Baser on the project.
"It's part of our renewable energy strategy," Attalla said.
Under the Illinois Climate Action Plan, the UI is committed to being carbon-neutral by 2050.
Related projects include the UI's solar farm along Windsor Road, a second one planned in Savoy, and another geothermal project that will be part of the North Campus Instructional Facility going up at the corner of Springfield and Wright streets in Champaign.
The university is also doing a feasibility study to convert the UI President's House to geothermal heating and cooling, Attalla said.
The North Campus Instructional Facility will have a traditional geothermal field, with holes drilled 350 feet deep under the Bardeen Engineering Quad to help bring up water to heat the building in the winter and cool it in the summer. It will cover about half of the building's cooling needs, he said.
That deeper system can supply more energy than the pilot project being used at the Hydrosystems Lab, Attalla said.
But the foundation method is also more space efficient, Baser said.
The real value of the project is long-term, as researchers study how the system performs, Attalla said.
"The outcomes of this project will be converted into design guidelines for future installation of energy foundations, which will significantly contribute to the sustainability of the campus," he said.
Baser called the project an "invaluable opportunity" to study how the system works under certain hydro-geological conditions. Specifically, researchers will look at how the foundation performs in the glacial tills of Illinois, "so that we can scale and extrapolate the findings and lessons learned in the future projects on campus and further in the Midwest."
Geothermal systems use the constant underground temperature to provide heating and cooling at remarkably high efficiencies, circulating fluid through heat exchangers in the ground leading to a heat pump in the building, officials said.
In the pilot project, the heat exchange occurs between surrounding soil and energy foundations.
During installation, Baser will install sensors to measure and monitor the temperature and strains within the foundations and see how the system is performing, she said.
Baser is involved in a similar project in Brazil funded through a UI collaborative grant with Professor Cristina de Hollanda Cavalca from the University of Sao Paulo, which has a different type of soil.
The $33.57 million renovation and addition to the hydrosystems lab, 301 N. Mathews Ave., which opened in 1967, is expected to be completed in the summer of 2020.
The third-floor bridge connecting to Newmark Lab will provide seating for students and faculty to collaborate and a connection to an alumni center at Newmark.
The Department of Civil and Environmental Engineering will also use the "smart bridge" as a teaching tool, installing sensors to monitor its movement and teach students about the effects of dynamic forces on infrastructure, officials said.
The 13,000-square-foot addition will more than double office space in the building and provide hands-on instructional labs, new classrooms and an elevator to comply with accessibility requirements.