Detection and Acceptance of Demand-Responsive Lighting in Offices with and without Daylight

摘要

Participants (N = 33) in an office laboratory were exposed to an initial baseline electric lighting level of 400 Ix on the desktop. The electric lighting was dimmed smoothly over 10 seconds. During the dim, and for 30 seconds afterwards, the participant performed a computer-based proofreading task. The participants indicated if they had noticed the change, and whether the lighting conditions were acceptable. This was repeated over multiple trials, with dimming from 0 to 80 percent, and with or without daylight. The level of dimming not noticed by occupants was 20 percent with no daylight, 40 percent with relatively low prevailing daylight, and 60 percent with high prevailing daylight (or, alternatively, an amount which represents 20 percent of total light level). The level of dimming that resulted in conditions that were still acceptable was 40 percent with no or low daylight, and 80 percent with high prevailing daylight. These results may be used to develop guidelines for using lighting in demand response actions. They suggest that dimming lights can contribute large electricity demand reductions during periods of grid stress without major inconvenience to occupants.