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U.S. Department of Energy
Office of Scientific and Technical Information

The Usefulness of Bi-Level Switching; Original Technical Note: November 1998. Revised August, 1999

Technical Report ·
DOI:https://doi.org/10.2172/764348· OSTI ID:764348

California's Title 24 Energy Efficiency Building Standard requires multiple lighting level control in all individual offices. Usually, this requirement is fulfilled using bi-level switching. With bi-level switching, each office occupant is provided with two wall switches near the doorway to control their lights. In a typical installation, one switch would control 1/3 of the fluorescent lamps in the ceiling lighting system, while the other switch would control the remaining 2/3 of the lamps. This allows four possible light levels: OFF, 1/3, 2/3 and FULL lighting. Because it has been required by building code since 1983, bi-level switching is common in California office buildings. However, there is no published evidence showing that occupants sometimes use just one switch rather than just switching on both switches when entering the room. Consequently, some have questioned whether bi-level switching is a necessary or desirable requirement for typical office buildings. In fact, the draft national standard, ASHRAE Standard 90.1-1989K apparently does not require bi-level switching at all.

Research Organization:
Ernest Orlando Lawrence Berkeley National Lab., CA (US)
Sponsoring Organization:
USDOE Assistant Secretary for Energy Efficiency and Renewable Energy. Office of Building Technology, State and Community Programs; GENERAL SERVICES ADMINISTRATION, PACIFIC GAS AND ELECTRIC (US)
DOE Contract Number:
AC03-76SF00098
OSTI ID:
764348
Report Number(s):
LBNL--44281; LG-215
Country of Publication:
United States
Language:
English