Dynamic Closed Loop Geothermal System Revolutionizes Energy Efficiency in Chicago School District

North Shore School District 112, located in the northern suburbs of Chicago, is making history as the first in the nation to power its schools with a Dynamic Closed Loop (DCL) geothermal system. The groundbreaking installation sets a new standard for energy efficiency in K–12 education — slashing emissions, lowering costs, and redefining what’s possible for sustainable learning environments.

Like many schools in the nation faced with aging infrastructure, North Shore School District 112 was looking for an innovative solution that would not only address immediate needs, but also serve generations of students into the future.

“The inspiration for green energy and saving taxpayer dollars was at the heart of our project,” said Dr. Michael Lubelfeld, superintendent, North Shore School District 112. “Trane's implementation of the DCL technology aligns perfectly with our strategic agenda and core values of sustaining both education and the environment.”

Green Energy

Unlike traditional geothermal systems, DCL technology harnesses the superior heat transfer properties of flowing water, requiring significantly less physical space and making it ideal for suburban school settings. The DCL system offers a space-saving energy capture field that reduces environmental disruption, aligning with modern sustainability goals.

“DCL relies on an aquifer for its heat absorption and rejection, and aquifers may exist at desired flow rates at varying depths based on the proposed location,” explained Andy O’Fallon, turnkey project developer at Trane. “This system uses 3 DCL wells. If aquifer flow rates meet the ideal predicted design, it’s possible to produce approximately 75 tons maximum of cooling (heat rejection) and 25 tons maximum of heating (heat absorption) per well at full capacity. A similar traditional geothermal system may need 50 traditional geothermal wells to meet the same capacity. This site did not have the land area to accommodate the traditional geothermal option.”

O’Fallon noted that the building’s Trane water-source heat pump HVAC system was already designed to accommodate a future geothermal energy source. In this design, each zone of the building can independently heat or cool using its own small refrigeration systems which, in turn, heat or cool the glycol loop throughout the building. Once the loop falls below or rises above the operational range, the DCL geothermal can either heat up or cool down the loop, depending on what is needed. The building also has code-required backup boilers to temper the loop during the coldest design days if the geothermal is at capacity.

“The planning process was accelerated due to this building already being under a large-scale renovation, which included Trane’s design and turnkey implementation for a water-source heat pump HVAC system,” O’Fallon said. “The geothermal component, which was originally planned for a future date, was requested by the school district to be completed while the building was already under construction, and Trane agreed to get it done. We engaged a geothermal consultant and determined that this site was feasible, then proceeded with the design and construction. With a tight timeline, equipment lead times for custom code-required well components and equipment shipped from overseas became a significant challenge. This, in addition to performing the drilling at this site while other trades were finishing their work created some complex scheduling challenges.”

O’Fallon added that the natural geology of a site greatly determines how fast drilling can occur — even between wells drilled in the same area. “[On this site] some wells had more dense rock and slowed the drilling process, while other areas were more porous, and the drilling went faster.”

Due to the site location being in the middle of a suburban neighborhood, O’Fallon noted that a lot of attention was given to the control of water and cuttings produced by the drilling process. “Pits had to be dug, and fluid directed by trenching to a designated area where it could evaporate naturally or be pumped out. This mixture of primarily water and powdered rock is naturally non-toxic; however, it can create pooling and mud if not managed properly.”

The innovative approach, combined with strategic use of federal, state, and local incentives, made the DCL system a financially viable option for the school district. North Shore School District 112 realized over $3 million in savings on a $6.67 million HVAC investment —  a return of as much as 50%.

A Duplicable Approach 

“This project is potentially transformative for educational markets nationwide,” said Patrick Heneberry, Trane Services account executive. “When you combine the various available incentives with Trane’s experience in sustainable systems and our consultative approach, we’re the ideal choice for innovative educational institutions.”

 O’Fallon added that the North Shore School District 112 system could be easily scaled to accommodate a single building or a campus of buildings, given the appropriate hydrogeological conditions. “The main consideration for a building owner is if their HVAC system is designed for the use of a water or glycol loop for heat absorption and rejection.”

The Chicago DCL system is expected to reduce the district's carbon footprint by approximately 30% while providing more consistent and comfortable learning environments. With the potential to offer school districts significant annual savings through reduced energy consumption and lower maintenance costs, the DCL system offers a compelling ROI and a clear path to a more sustainable future.

“Being among the first school districts in Illinois to have geothermal and the first in the United States to install the DCL technology is exactly what we want for our schools, students, and community,” said Dr. Monica Schroeder, deputy superintendent, North Shore School District 112. “This pioneering project serves as a model for other K-12 schools nationwide seeking to reduce their carbon footprint and lower operating costs. The project is a testament to how innovative technology can be leveraged to meet both educational and environmental objectives.”