It’s well-known that automatic shut off of lighting in large commercial buildings helps facility managers and building owners save energy and money. State energy codes mandate the use of control panels or occupancy sensors in new buildings for this purpose. According to the U.S. Environmental Protection Agency (EPA), Lighting Research Center (LRC) and California Energy Commission (CEC) publications, energy savings from using such devices can range from:
- 17-29% in Break Room
- 36-52% in Classroom
- 22-65% in Conference Room
- 25-50% in Private Office
- 30-75% in Restroom
While automatic shut-off provides increased savings for customers, research suggests implementing advanced strategies available with manual controls like switches can really turbocharge both energy savings and return on investment. For instance, the 2008 California Lighting Technology (CLTC) study indicates that both Manual-On and bi-level switching with automatic on of 50% of lighting offer dramatic increases in energy savings. Combining both automatic shut off and manual on control strategies results in up to 52% additional savings when compared to just one control strategy. Researchers found that the best practice control scenario is to have one light level come on automatically based on occupancy, while the other remains off unless manually activated.
ASHRAE Standard 90.1-2010 recognizes the value of these findings in its latest version, by mandating the following requirement: “Any automatic control device shall either be manual on or shall be controlled to automatically turn the lighting on to not more than 50% power, except in the following spaces where full Automatic-on is allowed:
* Public corridors and stairwells
* Restrooms
* Primary building entrance areas and lobbies and
* Areas where manual-on operation would endanger the safety or security of the room or building occupant(s)
Manual-On operation has a huge potential for saving energy and these savings help gain LEED points for better energy performance.
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