Energy Efficiency and Lighting Control
Lighting controls are necessary in any lighting system; without controls, it is impossible to turn lights off or on, or to change the lighting levels. Controls are either manual, such as a single pole switch or a residential type dimmer for incandescent lamps, or automatic, such as a time clock or photocell. Included in the automatic category are occupancy sensors that detect movement or heat and turn lights on when a space is occupied and off when it is vacant, and computerized energy management systems that are programmed to operate lighting systems on a predetermined schedule. [Lindsey 1991; IES, 1993]
McIlvaine et al. (1992) explain the advantage of programmable control systems in cleanrooms.
Significant savings in cost can be achieved if the lights are turned out in the cleanroom when it is not in use. A programmable control system can be readily applied to lighting loads with a payback period of less than one year, depending on actual usage. Obviously, the same savings can be achieved by merely turning off the switch at the end of the day's operation. The programmable control system, however, will rarely forget to turn off the lights.
The next sections will address a few energy-efficiency strategies that are considered cutting-edge, state-of-the-art technologies yet are also reliable and have proven track records.