Centreville High School
6001 Union Mill Rd
Clifton, VA 20124
Centreville High School in Fairfax County, Virginia is the academic home for 2,220 high school students and a staff of 211 professionals. The students are known for their high academic performance and their championship sports teams.
The 327,000-square-foot school building was also known to facilities managers as having a champion's appetite for energy. The building opened in 1988 and by 2000 it was clear that the energy consumption was a problem that needed a concentrated effort to fix. Because the building was in good overall condition compared to the district's other 24 high schools, a total renovation of the building was not seen as a viable solution. An approach that tackled the energy use and aging mechanical systems in multiple phases was the winning strategy.
In 2003, Centreville was included in the first phase of an energy performance contract with Noresco, an energy service company, along with 14 other high energy consuming schools. Based on the success of the first phase of this program, the performance contract was ultimately implemented at 107 FCPS buildings over a 3-year period making up 10.4 million square feet of space and a total investment of $19 million dollars.
At Centreville High School, the performance contract included retrofitting T-12 fluorescent lighting with magnetic ballasts to T-8 lighting with electronic ballasts. Metal halide gym lighting fixtures were replaced with high output T-5 fluorescent fixtures which dramatically improved the lighting levels and quality--a bonus that was appreciated by the physical education department and sports teams. Occupancy motion sensors were installed in rooms to automatically turn off lights when the spaces are unoccupied.
The ESCO contract also included re-calibrating the original pneumatic thermostats and controls, tuning up the boilers, and installing a smart meter on the incoming electric service.
In 2005, the two cooling towers were replaced due to their deteriorated condition. The new cooling towers are energy efficient and the project included variable frequency drives (VFDs) and modulating controls on the tower fan motors to conserve energy and reduce wear and tear on the motors.
Also in 2005, a 10,000-square-foot, 8-classroom modular building was constructed to accommodate the growing student enrollment. In 2007, Web-accessible Proliphix programmable thermostats were installed in the modular building to allow for temperature setback, fan control, and outside air damper control of the heat pumps. Modular classrooms temperatures are set back/set-up on a schedule programmed over the network from the central office at nights, weekends, holidays, and snow days to conserve energy. Outside air dampers are opened only during occupied hours. Teachers can temporarily override the thermostat to adjust to their particular comfort level or to work during off hours. Based on the success at Centreville High School, FCPS has since installed these thermostats in 459 classrooms in 40 modular classroom buildings.
In 2007, the original boilers and hot water circulating pumps were replaced for maintenance purposes with new boilers. High efficiency motors were selected for the hot water circulating pumps.
In 2008, the two 400 ton chillers and 18 associated condenser, primary chilled water, and secondary chilled water pumps were replaced. The new chillers and pumps were selected to be energy efficient. VFDs were installed on all secondary zone pumps. The VFDs replaced the original and inefficient pump discharge choke valves that controlled chilled water flow to the air handlers. Also included in the chiller replacement project was a chilled water plant management control system that optimizes the staging and loading of the chillers and the cooling towers for peak operating energy efficiency.
In 2009, the capstone energy efficiency project replaced original hybrid pneumatic/electronic building control system with a state-of-the-art Delta direct digital control (DDC) system. The control system included replacing all VAV box controls, hot and chilled water valves, and outside air damper actuators. Classrooms have adjustable thermostat sensors so teachers can adjust room settings to their individual comfort level within a few degrees of setpoint which improves occupant satisfaction with their room conditions. Also included in the project was replacing intake vortex vanes and discharge air dampers on air handling units with VFDs on fan motors, utilizing carbon dioxide-based occupancy sensors in the gymnasium and auditorium for demand control ventilation, recommisioning exhaust air recovery ventilation units for the locker rooms, and a total air balance of the building. The VFDs for the chilled water plant and the chiller plant control system were fully integrated with the new DDC control system utilizing a BACnet communication interface.
Overall energy use at Centreville High School has declined from 73 KBTU/sf in 2001 to 52.5 KBTU/SF in 2009 making it the most energy-efficient high school of the 25 in the FCPS district.
Located in northern Virginia, Fairfax County Public Schools is the nation's 12th largest school district with 173,570 students attending 197 schools and centers. The Energy Management section within Office of Facilities Management (http://www.fcps.edu/fts/facmanagement/energy/index.htm) is responsible for minimizing the energy and water utility cost through development and implementation of conservation programs. FCPS has had an active energy management program since 1978.
Please note: Narrative information in this profile has been provided by Fairfax County Public Schools or a representative of this facility. Other building information was verified and submitted to EPA at the time of application. Building energy performance, operating characteristics, and ownership/management may be subject to change over time.
Fairfax County Public Schools
Fairfax County Public Schools
Year(s) Labeled (Rating):
Facility Type: K-12 School
Total Floorspace: 337003 sf
Year Constructed: 1988
Contract Type: Multiple Contractor Contracts
Financing Type: Public Bond
|Stage 3-Load Reductions|
|Stage 4-Fan Systems|
|Stage 5-Heating and Cooling Plant|