Whenever an area is left unoccupied for any length of time, the lights should
be turned off. When people leave their offices for a meeting or for lunch,
they should turn off the lights in their own work space if switching is available.
Similarly, people leaving restrooms or storage areas unoccupied should turn
lights off. Some companies have had great success by using a label or sign next
to the light switch reminding people to turn it off.
With fluorescents, lamp life is shortened by being turned on and off frequently. However, remember that energy cost savings far outweigh the cost of these lamps. Remember also that mercury vapor, metal halide, and sodium lamps take longer to start than fluorescent and incandescent lamps and often must wait several minutes after being turned off before they can restrike. Where the delay might cause problems, it must be taken into account when making a decision to turn these lights off.
Turn off those lights nearest the windows whenever there is enough natural light if switching allows this control. If you have shades or blinds that can be opened, the sun they let in will also add warmth and reduce the load on your heating system in winter. On the other hand, this solar heat may be unwanted in summer; but you may find that so much electricity can be saved by switching off lights that it will pay to install special film, shades or blinds to reduce heat gain yet let the natural light in during the warm months.
