by Deborah Harter Williams
Clovis Unified School District, north of Fresno, celebrated last year with a rebate of more than $100,000 from PG & E. Eight schools in the district participated in a pilot energy management program: Clovis High School, Kastner Intermediate School, and Cole, Maple Creek, Mountain View, Valley Oak and Weldon Elementary Schools, as well as the Center for Advanced Research and Technology (CART), a career-specific, lab-based school.
System Control from a Laptop
The first step was to activate the new energy management system. The system monitors and controls electric lighting and HVAC (heating and cooling) systems through a central web-based port. This lets district’s energy manager, Gary Foster, access real-time energy data from any school or the entire district with a laptop computer. From there he can remotely turn electrical systems on and off.
Heating and Cooling Control
Heating and air conditioning in both permanent buildings and temporary classrooms are where the biggest energy savings come from. All portable classroom units were retrofitted so HVAC systems could be remotely controlled. Then pneumatically-controlled ventilators, which used to stay on all the time, were refitted with individual relays and tied into the system. This allows for individual on-off scheduling for each room’s unit.
Air handling units were also refitted to enable remote temperature reset and individual unit scheduling. Temperature sensors for heat and air conditioning replaced the on-off switches for all HVAC units.
Let there be light – but only when we need it
At CART, in the atrium area, they installed fully automated lighting controls with photocells. These photocells detect the level of daylight and turn off the lights in the building if there is enough natural light available. Also at CART, a temperature-reset schedule was implemented. This means that during times when staff and students are not around, such as lunch hours, the air conditioning or heat can be turned down.
This program provided an annual savings of almost 600,000 kilowatt hours or nearly 9000 therms. A therm is the equivalent of 100,000 BTUs and 100,000 BTUs is enough to heat a 1600-square foot (medium sized) house, so picture 9000 houses. The savings, plus a rebate of $105,115, meant the project would pay for itself in less than 15 months.
The district’s 11 swimming pools now have heat-retaining pool covers, which saves nearly 2000,000 therms. With a PG&E rebate of some $58,000 covering half the capital cost, the payback on the investment shows up in less than 15 months.
T5s for Savings
Now the district is looking at retrofitting lighting of the district’s 16 full-sized gyms. CUSD plans to replace the current metal halide fixtures in all the gyms with T5 fluorescent fixtures. T5 lamps have the potential to cut energy use in lighting by more than 65%.
Green Smart School
The district has also submitted an application to build a new energy center at Buchanan High School. This would be a place where students can learn about energy-efficient technology and get training for new-economy “green” jobs.