Imagine a school where the building itself is a core part of the curriculum – a dynamic environment designed not just to house students, but to actively teach them about sustainability and environmental stewardship. This isn’t a futuristic concept; it’s the reality at The Academy for Global Citizenship (AGC) near Chicago. Students here don’t just learn *in* a building; they learn *from* it.
AGC was conceived from the ground up to push beyond minimum code requirements, creating a space with minimal environmental impact that simultaneously fosters exceptional student success. This ambitious project began with a fundamental understanding: to build truly high-performing, healthy learning environments, we must first grasp how typical schools operate and consume energy, and then dare to design differently.
The Challenge: Understanding the Typical School Landscape
Before charting a new course, high-performance school designers often look at the baseline. In the US, educational buildings account for a significant slice of the non-residential building sector’s energy pie – 13%, according to the Energy Information Administration (EIA[1]). This constant demand for new schools presents a continuous opportunity to integrate leading-edge technology and design principles that benefit both occupants and the planet.
Yet the operational profile of a typical school presents a unique challenge. While operating year-round, requiring constant conditioning, spaces like classrooms often sit empty for more than half the school day due to varied schedules and student movement. Conventional systems, unable to adapt dynamically to these occupancy swings, end up wasting enormous amounts of energy conditioning empty rooms, inflating operating costs and needlessly increasing carbon emissions. This inefficiency was a key problem AGC sought to solve.
Pinpointing the Energy Hog: Why HVAC Matters Most
Digging deeper into EIA data reveals a critical target for energy savings: heating, ventilation, and air-conditioning (HVAC). Accounting for over half of the typical school’s energy consumption (with space heating alone representing over 40%), the HVAC system became a primary focus for the AGC design team. Minimizing energy use and operational carbon hinges significantly on designing and operating HVAC systems intelligently.
Beyond Efficiency: Selecting HVAC to Boost Brainpower
But for a school, energy efficiency is only half the equation. The ultimate goal is education, and the learning environment itself plays a crucial role. The link between HVAC performance, particularly ventilation, and student cognitive function is well-documented.[2] Consider this: a well-designed mechanical ventilation system can supply four times more fresh air than simply opening windows. Furthermore, studies show that significantly increasing fresh air supply in classrooms demonstrably improves student concentration, memory, and reaction times – fundamental building blocks for learning. In practical terms, this means students in well-ventilated spaces can think faster, remember more, and stay more alert throughout the school day. AGC needed an HVAC system that could deliver both exceptional efficiency along with an optimal indoor environment to help students thrive.
DEMONSTRATION: Students at The Academy for Global Citizenship explore sustainability firsthand, learning from the building itself as part of their daily curriculum. (Courtesy of Tom Rossiter FAIA)
Raising the Bar: HVAC’s Role in Achieving the Living Building Challenge
Standard building codes rarely mandate Net Zero Energy or Carbon performance, nor do they set specific targets for student outcomes or comprehensively restrict potentially harmful materials in building products. Recognizing these limitations, the AGC team didn’t settle for code minimum. They voluntarily adopted the Living Building Challenge (LBC) early in the design process. Administered by the International Living Future Institute (ILFI), LBC is arguably the world’s most rigorous green building standard, demanding Net Zero energy and water, alongside challenging criteria for place, health, materials, equity, and beauty.
As Len Sciarra of Farr Associates, the project architects, stated: “The project aims to be a global exemplar of sustainability… it’s Net-Zero energy and water and is constructed with low carbon and non-toxic materials. It also provides daylight for 90% of the occupants and fresh air above the required code minimum. An air quality monitoring system and full access to all the building and site metrics are incorporated into the academic curriculum.” This integration of building performance into the curriculum is key to AGC’s mission.
Chicago-based engineering consultants dbHMS took on the challenge of designing an HVAC system to meet these ambitious LBC goals. Dispelling any notion that HVAC technology lags in sustainable innovation, dbHMS crafted a solution using sophisticated, available technologies tailored to meet LBC imperatives for energy, health, and materials.
The Solution in Action: Dedicated Outside Air Systems (DOAS) at AGC
The cornerstone of AGC’s high-performance HVAC strategy is a Dedicated Outside Air System (DOAS) approach. Three advanced DOAS air handling units form the system’s core, specifically engineered to:
- Slash energy and carbon: Ultra-efficient energy recovery, low-energy fan motors, and intelligent controls minimize energy draw.
- Ensure healthy indoor air: Precise ventilation control based on real-time conditions ensures optimal air quality.
- Utilize responsible materials: The units carry Declare labels, certifying they avoid harmful “Red List” chemicals, aligning with LBC’s stringent materials requirements.
- Demand Control Ventilation (DCV): A critical element is DCV. Instead of supplying constant airflow everywhere, CO2 sensors monitor individual zones (classrooms, offices). Variable volume dampers downstream of the DOAS units modulate airflow based on actual occupancy. When CO2 levels rise (indicating more people), dampers open to deliver more fresh air; when levels drop (fewer people), airflow decreases, saving significant fan energy. It’s a system that breathes with the building’s occupants.
- Smart Pressure Control: Managing airflow across dozens of independent zones requires precise duct pressure control. The DOAS units constantly adjust fan speed based on downstream pressure sensors, ensuring that rooms far from the unit receive just as much fresh air as those nearby, preventing over- or under-ventilation while optimizing energy use.
- Mastering Heat Recovery: With heating being the largest energy load, efficient heat recovery was paramount. AGC’s DOAS units employ advanced rotary heat exchangers that recapture over 80% of the heat from the exhaust air stream, transferring it back to the incoming fresh air, far exceeding typical code requirements. The rotation speed adjusts to precisely control supply air temperature, minimizing the need for additional heating. Sophisticated onboard controls even prevent frost formation during cold weather, eliminating the downtime and energy penalties associated with defrost cycles in lesser systems.
As of late 2024, the occupied building was undergoing final performance verification for its Living Building Challenge certification, demonstrating these systems in real-world operation.
| DOAS Unit | AHRI 1060 sensible effectiveness (Summer/Winter) |
| 1 | 83.9% / 85.5% |
| 2 | 88.8% / 90.1% |
| 3 | 87.5% / 88.8% |
Operational Sustainability Curriculum and Culture
At AGC, sustainability isn’t just a policy; it’s woven into the very fabric of the school’s culture and curriculum. “With a mission of fostering environmental stewardship, the building itself serves as a teaching tool,” confirmed Sciarra, highlighting the exposed, labeled systems and windows into mechanical rooms. Through AGC’s transparent building design, students gain firsthand understanding of the connections between mechanical systems, personal comfort, and environmental impact – knowledge that textbooks alone cannot convey.
As they observe innovative systems in action and track real-time performance data, students develop practical insights that may inspire future careers in architecture, engineering, or environmental science, demonstrating how thoughtfully designed buildings can simultaneously shelter occupants and cultivate both academic achievement and environmental responsibility in the next generation.
Acknowledgements
The author wishes to thank Len Sciara of Farr Architects and Marcos Guerrero of dbHMS for their support and contributions to this project and to this article.