The Worcester School District was facing a problem playing out in conference and committee rooms all over the Commonwealth, and all over the country: How to maintain the long-term viability of a capital asset while not breaking the budget. The South High Community School, built in the 1970s, desperately needed an HVAC upgrade. The existing system, dating back to the school’s construction, was an outdated multi-zone rooftop unit that left classrooms too cool in the winter and too warm in the spring and fall.
Not only was this inefficient system making the classrooms uncomfortable, but it was also leading to higher utility bills. To complicate matters, any new system would need to utilize the school’s existing roof curbs and ductwork. After meeting with the Worcester School District, Trumbull Campbell Associates reviewed their needs and the specific nature of the application.
To meet these needs the team at Trumbull Campbell Associates recommended packaged DX/gas AAON energy recovery units with variable-frequency drives and modulating gas heat. The AAON units allowed them to recover heat and cooling from the energy recovery wheels, reducing the cooling tonnage and gas consumption required to heat and cool the space—and cutting utility bills.
The Airxchange energy recovery wheels were calculated to save approximately $1.2 million in today’s dollars over the average life of the new rooftop units. For roughly the same price as a larger more energy intensive rooftop unit, Trumbull Campbell Associates and AAON can provide the same amount of work with a smaller, wheel- based unit that performs with over 40% increase in efficiency. This translates to significant energy savings over the life of the equipment.
Further, Trumbull Campbell Associates worked with the installation contractor to provide an adapter curb that would allow air distribution through the existing multi-zone ductwork directly from the AAON unit, thus avoiding ductwork modifications that would have significantly impacted the project cost and resulting payback.
The AAON system recommended by Trumbull Campbell Associates—an environmental as well as technological upgrade over the legacy system it replaced—allowed the School District to cut costs while providing a safe, healthy and comfortable environment for teachers and students.