When deciding on a lighting system, schools should consider not only the installation cost, but also the costs of operating and maintaining it. The initial cost includes the capital cost of luminaires, lamps and electrical power circuitry, as well as installation labor, tooling and support hardware.
In general, more expensive luminaires operate more efficiently, provide more light per dollar invested, exhibit good maintenance characteristics, and can stand up to abuse without suffering the damage that might be expected from lightweight, inferior materials and coatings. But the initial cost of a lighting system makes up only five to 10 percent of a system's overall cost over a 20-year life span.
Relamping in groups rather than one at a time often allows for savings in labor and purchasing costs. Lamps should be replaced before the end of their rated life.
In general, reducing the numbers of lighting fixtures reduces costs for maintenance, lighting energy and air conditioning, as well as initial purchasing cost. In locations where luminaires are not needed for long periods, schools should consider using switches that de-energize or dim the luminaires, and re-energize and provide light instantly when someone enters the room.
When replacing existing fixtures, consider installing:
-Fluorescent luminaires with specular reflectors.
-Fluorescent luminaires with clear acrylic lenses, polycubed louvers or refractive grid lenses.
-Fluorescent luminaires with T8 fluorescent lamps.
-Four-foot fluorescent luminaires with two-lamp, three-lamp or four-lamp electronic ballasts.
-Exit signs that contain Light-Emitting Diodes (LEDs) instead of incandescent or fluorescent lamps.
-High Intensity Discharge (HID) luminaires with high-pressure sodium lamps to replace mercury vapor HID luminaires.
-Proximity controls with dimmers or switches to save energy.