Chraibi and colleagues investigated employee responses to dynamic workplace lighting that dims over a workstation when the person working there leaves their seat and brightens when someone returns to that workspace. Installing dynamic lighting can be important because “Sensor-triggered control strategies can limit the energy consumption of lighting.” Via data collected in a mock-up office, the researchers learned that when “the participants performed an office-based task [and] the luminaire above the actors’ desk was dimmed from approximately 550 lx to 350 lx (average horizontal illuminance), and vice versa. . . . the noticeability of light changes due to dimming, increases when fading times become shorter. Dimming with a fading time of at least two seconds was experienced as acceptable by more than 70% of the participants.” During the data gathering periods there was “dimming up when occupancy is detected and diming down when a desk becomes unoccupied.” Of 6 lights in the test area, the intensity of only one varied, the light right above the workstation of a confederate of the researcher who entered or left the test area as instructed by the researchers. Data were collected from people sitting near that confederate and the lights remained on above the desks of the people answering the investigators’ questions. There was no natural light in the test area.
S. Chraibi, P. Creemers, C. Rosenkotter, E. van Loenen, M. Aries, and A. Rosemann. “Dimming Strategies for Open Office Lighting: User Experience and Acceptance.” Lighting Research and Technology, DOI: 10.1177/1477153518772154