When Ravinia Elementary School reopens in the fall following its extensive, $40 million gut rehab, it will be heated and cooled using a relatively unusual technique: a geothermal HVAC system utilizing the region’s massive aquifer hundreds of feet below the surface.
The school is the first of three in North Shore School District 112, which encompasses Highland Park and Highwood, that is planned to have the system installed, with the district touting the “cutting edge” system’s long-term energy cost savings and environmental benefits.
Superintendent Michael Lubelfeld described the system as a “milestone” for the district, saying it demonstrates its commitment to “innovation and sustainability.”
Sherwood Elementary is also in the midst of a $30 million renovation that will include the installation of the same geothermal technology, as will a future renovation at Wayne Thomas Elementary planned in the years ahead.
The installation and other extensive renovations to Ravinia will transform the oldest physical structure in the district, dating to 1913, into an example of “one of the most modern approaches to energy efficiency,” Lubelfeld said. The school’s capacity has also been expanded.
“Our students deserve facilities that reflect the high standards of their education,” Board of Education President Lisa Hirsh said in a district press release. “Investing in sustainable infrastructure sends a powerful message: We care deeply about their future, both inside and outside the classroom.”
Geothermal HVAC
Andy O’Fallon with Trane Technologies, which worked on the implementation of the geothermal system, explained how such technology works and how this system differs from others.
Typically, geothermal HVAC systems have hundreds of small holes, maybe several inches wide, drilled into the ground, and pipes circulate water to absorb or dissipate heat from the Earth, which has a much more stable temperature compared to above-ground. O’Fallon compared it to the fins on a computer’s heat sink.
It’s a technique that goes back to the 1970s and ’80s, O’Fallon said, although it had fallen out of favor, and there had been cases of poorly implemented systems where contaminated water was circulated through expensive equipment.
“Since then, the industry in general has learned a lot more about geothermal, and we have a lot more tools now to assess what’s in the Earth,” he said.
However, this technique has limitations and generally requires a large area from which to dissipate and absorb heat. Ravinia’s system gets around its spatial limitations by utilizing a handful of much larger holes, about 10 to 14 inches wide, drilled several hundred feet into the region’s massive underground aquifer. This way, heat can be drawn and dissipated from a vast area.
O’Fallon emphasized the system’s circulated water doesn’t come into contact with the aquifer water, meaning “minimal to no impact” on the environment.
“We’re not pulling it out of the ground,” he said. “We’re not treating it with anything.”
He talked about the various benefits of the system, including long-term savings from reduced energy costs and overall environmental benefits. Such systems reduce the need for fossil fuels for heating.
“It’s difficult in our area, because we get so cold outside,” O’Fallon said. “It’s so difficult to eliminate fossil fuels because most technologies can’t keep up.”
The school has two backup heating systems for the winter, one electric and the other powered by fossil fuels.
The implementation at Ravinia could mean similar technologies could be implemented at other districts as they “catch wind of this option,” O’Fallon said. The “relatively unknown” technology could begin to “gain some traction.”
“I think North Shore is way ahead of the game,” he said.
