Comprehensive Energy Efficiency Treatment
Efficiency measures qualified for nearly $385,000 in incentives from NSTAR and National Grid.
Milton Academy, an independent college preparatory boarding and day school, sought an increased level of efficiency in its mechanical, controls, and lighting systems.
Milton’s existing pneumatic controls system was outdated, inefficient, and expensive to operate. Much of the HVAC equipment throughout the campus was not controlled efficiently during unoccupied hours and school holidays. OpTerra installed appropriate digital BAS controls to the HVAC system including pumps, valves, air handling units (AHUs), chiller and heat exchangers, allowing scheduling strategies to be implemented on a zone basis, saving energy and eliminating the need for expensive compressed air to operate the pneumatic controls. OpTerra also installed variable frequency drives (VFDs) on AHUs and water circulation pumps, further reducing Milton’s energy consumption. These VFDs were programmed to reduce motor speed or turn motors off entirely in response to system pressure or during unoccupied hours. Annual energy savings achieved through the implementation of BAS controls and VFDs are over 600,000 kWh.
The existing lighting throughout Milton’s campus was predominantly T8 lamps with electronic ballasts. Sensors were only installed in select areas. In addition to the main goal of energy savings, OpTerra’s design also focused on standardizing lighting technologies and color temperature. Over 5,000 fixtures were retrofitted to High Performance T8 (HPT8) technology. Dual technology sensors installed throughout the campus allow for lights to switch off in unoccupied areas, further increasing energy savings. OpTerra also converted over 250 exterior metal halide and high pressure sodium fixtures to more efficient LED technology. Through these measures, OpTerra was able to reduce Milton’s annual lighting costs by nearly $66,000.
Energy efficiency measures designed and implemented by OpTerra reduced Milton’s electricity usage by over 20 percent and qualified for nearly $385,000 in incentives from NSTAR and National Grid.