School System Beefs Up Lighting

Officials of Utica Community Schools (Mich.) came to the realization recently that the district's 28 elementary school gyms could be more than just spaces for P.E. classes and basketball games and decided to use them as lunchrooms and auditoriums, as well as for dances, parties and other community events.

As such, the district decided to renovate the gyms, including updating the lighting systems so they would be appropriate for a variety of activities.

Originally, the gyms' lighting was provided by 400-watt high-pressure sodium (HPS) high-bay luminaires. For the gyms' new and varied roles, lighting systems would need to achieve different light levels using one set of luminaires.

When doubling as an auditorium, a gym's lighting requirement is 5-15 foot-candles. In its lunchroom capacity, the requirement is 30-40 foot-candles. And for the purpose of hosting P.E. classes and basketball games, 75-80 foot-candles are required. Multi-level switching could achieve these various levels, but such a solution required that Mike Gold, EAM Engineers, Troy, Mich., the designer of the new system, approach fluorescent lighting from a different angle.

High-intensity discharge (HID) sources, like HPS and metal halide, have become prominent in gym lighting thanks to high lumen values, compact size and long life. Newer fluorescent technology, like the T5 lamp, has introduced more lumens, smaller size—for better optical control—and longer life, according to Gold. T5 fluorescents also have much better color rendering than any HID light source. Combined with electronic controls, the T5 provides flexibility and instant starting capabilities.

Gold's requirements included luminaires with more than four lamps that could provide two levels of switching, plus a dimming circuit. He settled on a manufacturer that specialized in the custom design of industrial and commercial units. The vendor created a 2-ft. x 4-ft. troffer that housed five to eight 54-watt T5HO lamps and designed versions for surface or grid mounting. When all eight lamps are lit, the unit is said to generate up to 40% more lumens than standard 400-watt metal halide low- or high-bay luminaires.

One of the district's first gyms to sport the new lighting system was at Browning Elementary School in Sterling Heights. Twenty of the new troffers were installed here in a new grid-type ceiling, which offered more reflectance than the previous exposed structure. These luminaires were configured for five lamps each and contained a battery pack for emergency lighting. They were spaced every 12 to 16 ft. for a total of 3,840 sq. ft.

The Browning Elementary gym was finished last year. With all of the lights on, the total output reached almost 100 foot-candles—much higher than that of the old HPS system.

So far, five gyms have installed the system, and more will take advantage of it soon.