Study: Bilevel occupancy sensors save energy
A recent CLTC study demonstrates major energy savings for bilevel occupancy sensors.
Data released from a California Lighting Technology Center (CLTC) study show that bilevel occupancy sensors can achieve energy savings in many buildings. The Lighting Controls Assn. recently released the results of this study.
While the basic ON/OFF switch is not considered an energy-saving lighting control, it can be if at least two switches are used to control lighting in a space that is configured on two lighting circuits, giving the user a choice of two levels of light output.
Alternate rows, fixtures, or lamps can be switched, offering a choice of 50% and 100% light output. Or the center lamps can be switched separately from the outer lamps in three-lamp fixtures, offering a choice of 33%, 66%, and 100% light output. In one study by ADM Associates, the latter option was demonstrated to produce 22% energy savings in private offices.
At least one-half of the energy codes in the United States are based on the International Energy Conservation Code (IECC), which requires light level reduction controls such as multilevel switching or dimming in enclosed spaces such as private offices.
Occupancy sensors are just as simple-a switch married with a sensor to enable automatic switching based on whether the sensor detects the presence or absence of people. Occupancy sensing is a reliable method for generating energy savings: According to the Advanced Lighting Guidelines, occupancy sensors in private offices can produce up to 45% energy savings.