Engineering Below the Surface: The Walnut Hills Chiller Overhaul

When we think about designing educational environments where students can learn, grow, and thrive, our minds often wander to daylit classrooms, flexible collaboration spaces, or modern athletic complexes. However, some of the most critical work required to ensure safety, health, and comfort in our schools occurs entirely out of sight.

At Walnut Hills High School—home to the second-largest chilled water plant in the Cincinnati Public Schools (CPS) system—a reliable climate control system is vital to the daily learning environment. When CPS tasked SHP with replacing the school’s aging chilled water plant, our engineering team saw an opportunity to do more than just swap out old equipment. By combining rigorous data analysis, 3D modeling, and a smarter layout, we set out to build a more resilient, efficient system for the entire campus.

This engineering overhaul builds upon our long-standing partnership with the district to modernize Walnut Hills High School for 21st-century learning.

Historically, the school’s climate control suffered from a classic mechanical bottleneck. The original configuration dedicated two chillers to a traditional chilled water loop, while a third chiller handled a completely separate, warmer chilled beam loop. This division meant that if a single critical component went down for maintenance, the balance of the entire system was compromised.

Our team solved this vulnerability by shifting to a parallel “triplet arrangement.” We installed three identical chillers operating side-by-side, paired with a mixing valve to handle the chilled beam loop. Now, the system has a built-in safety net. If any single chiller needs to be taken offline for routine servicing, the remaining two units automatically step up to carry the load—ensuring uninterrupted comfort for students and staff alike.

Replacing massive industrial equipment is rarely a straightforward task, but Walnut Hills presented a unique spatial puzzle: the plant’s three original modular chillers—totaling a massive capacity of nearly 1,000 tons—were located 20 feet underground.

To avoid costly surprises or field adjustments during construction, our team relied on precision data over guesswork. We conducted a comprehensive 3D scan of the subterranean room, creating an incredibly accurate “point-cloud” dataset. By importing this data directly into our Building Information Model (BIM), we generated a perfect digital twin of the space. This allowed our engineers to test configurations and verify clearances down to the inch before a single piece of hardware was ordered.

It is easy to look at an old 1,000-ton system and assume it needs to be replaced with an identical capacity. However, a core philosophy at SHP is letting objective data dictate the design, rather than falling back on old habits.

Instead of copying the original specifications, our team ran a detailed, campus-wide load calculation to analyze the actual heating and cooling demands of the modern campus. The data revealed that the school could be served just as effectively with a more streamlined output.

Right-sizing the plant in this manner eliminated wasted energy, lowered long-term utility costs, and ensured the district maximized the value of its infrastructure budget.

Once the engineering blueprints were finalized, the physical installation required some serious logistical gymnastics from the construction team. Because the equipment sat two stories below grade, crews had to temporarily remove the roof of a delivery shaft structure to open a direct path to the surface.

From there, heavy rigging teams hoisted the massive old units out and carefully lowered the new, high-efficiency chillers down through the shaft for final installation.

At the end of the day, mechanical upgrades aren’t just about pipes, valves, and tonnage. They are about creating a reliable foundation where education can happen without interruption. By pairing forward-thinking engineering with the right technology, Cincinnati Public Schools optimized its back-of-house operations so administrators can keep their focus exactly where it belongs: on the students.

As Lekendalle Heights, Facilities Manager for Cincinnati Public Schools, noted:

Looking to optimize your campus infrastructure or utilize 3D scanning for an upcoming renovation?