High School Earns an â€˜A' for Energy Efficiency
Located approximately 30 miles northwest of Chicago, District 214 is the second largest high school district in Illinois, serving more than 250,000 residents in several communities. Built in 1973, Buffalo Grove is one of six comprehensive high schools in the district and has an enrollment of more than 2,100 students.
THREE SPECIFIC GOALSTo resolve energy management and other issues at Buffalo Grove and all its schools, the district partnered with ITG Solutions Inc., of Homewood, Ill., the local Tour Andover Controls (TAC) representative. The district had three specific objectives: upgrade all temperature control systems, both retrofit and new construction; add access control at critical locations; and provide multiple operator workstations on the school district's existing local area network (LAN).
ITG recommended a TAC building automation system (BAS), designed to meet the district's needs. This solution upgraded the district's aging facilities to meet present building control requirements and energy management initiatives, while remaining within a tight budget.
Doug Smith, building and grounds supervisor at Buffalo Grove, monitors the entire building from a single workstation in his office outside the school's central chiller plant. He said he can adjust individual classroom temperatures, modify the school bell schedule, acknowledge alarms, and troubleshoot potential problems with the boilers, classroom unit ventilators, VAV units, pumps, fans, etc., with just the click of the mouse.
Smith's workstation is connected via the district's LAN to a central workstation and file server in the district's central maintenance office, where all alarms at Buffalo Grove, or any district school, are monitored simultaneously.
Relying on the new BAS, Smith said he does not spend his day running around the high school addressing complaints about the temperature in the building. Even on a typical 0°F winter day, he said his eight boilers and two circulating pumps are humming along under peak conditions without a glitch and still at only 65 percent capacity.
Occupancy sensors installed in each classroom at Buffalo Grove integrate lighting and VAV control. When a classroom becomes unoccupied, the lights shut off after a predetermined time period, heating/cooling returns to its unoccupied set point, and VAV dampers are positioned to minimum setting.
SUMMER SCHOOL SAVINGSAdditional energy savings are realized during the summer school session, according to Smith. Because the district only uses about one-fifth of the school building for summer classes, he can cut energy by turning on only the rooftop units needed in one area.
Buffalo Grove also uses an ice storage system, designed to produce chilled water for air conditioning. This system was chosen for its potential to reduce the impact of demand charges through utilization of lower off-peak energy rates.
According to Smith, during eight months out of the year, the system makes ice at night when electricity costs are the lowest per kWh and there are no demand charges. The following day, the system melts the ice to make chilled water, in lieu of running chillers, when electricity costs are the highest per kWh and demand charges are in effect.
According to Seymour Schwartz, the district's director of buildings and grounds, the ice system is probably the school's greatest money-saving device. He said that the air conditioning at Buffalo Grove runs approximately $10,000 less per month than air conditioning at a school in the district without an ice system.
Energy savings since the installation of the new BAS at Buffalo Grove have been impressive, too. According to Schwartz, electricity costs at the school went from an average annual cost of $400,000 to $318,000 in the first year, despite the fact that after the renovation lighting levels doubled and fresh air requirements tripled.
"Utility money is wasted money," said Schwartz. "We have a $2.5 million gas and electricity budget district-wide. Our goal is to reduce this amount without affecting comfort and health."
The effective use of the school's BAS has played a major part in meeting this goal, he said.
For more information, visit www.andovercontrols.com.
Publication date: 05/29/2006