The Solutions

One of the main project challenges was preserving Memorial Elementary’s historic integrity while integrating modern HVAC technology. Initially, the client sought a straightforward like-for-like system replacement. However, through a comprehensive life cycle cost analysis, CMTA demonstrated that a ground source heat pump (GSHP) system would provide a more cost-effective and sustainable solution. The decision to transition to geothermal was the result of a collaborative selection process that engaged key stakeholders—including the maintenance director, construction director, and an owner’s representative—ensuring alignment with the project goals and the district’s long-term vision.

Key upgrades included replacing the outdated propane-fired boiler and fluid cooler system with the GSHP solution, complemented by a decoupled Dedicated Outdoor Air System (DOAS) for efficient fresh air delivery. Twinned console heat pumps replaced classroom unit ventilators, providing greater resiliency, energy savings, and insulation by eliminating external penetrations. Similarly, the gym’s four gas-fired rooftop units (RTUs) were replaced with two heat pumps, delivering staged operation to efficiently meet variable loads. Envelope enhancements further contributed to energy savings, including closed-cell polyurethane foam at wall-to-roof junctions to reduce infiltration.

Special attention was given to preserving the school’s historic facade. As a result, DOAS units were strategically positioned to remain hidden—one behind the main building on the gym’s 80-year-old timber frame barrel roof and another on the classroom wing roof, both concealed without unsightly screens. New chases were carefully designed to route ductwork without disrupting the building’s decorative murals. These thoughtful innovations honored the school’s architectural heritage while significantly improving its energy performance and indoor environment.

A new building automation system (BAS) was also installed and commissioned, enabling occupancy scheduling, start-time optimization, and demand-based control for precise HVAC operations. Ventilation systems were upgraded with strategically placed Energy Recovery Units (ERUs) in high-demand spaces like the cafeteria, gym, and basement classrooms. Integrated into the BAS, these units provide precise temperature and humidity control and dynamically adjust to maintain CO₂ levels below 700 PPM, enhancing indoor air quality to provide a healthy and comfortable learning environment. Additional improvements included converting the entire building to LED lighting and transitioning to 100% electric operation, eliminating fossil fuels and boosting efficiency.