Determining photosensor settings for optimum energy saving of suspended lighting systems in a small double-skinned office

Abstract

SUMMARY A photoelectric dimming control system applied to a suspended direct/indirect and indirect lighting system was analyzed to determine effective control options in a small office with double-skin envelope. Computer simulations were performed for photosensors positioned at three different locations with three specific configurations under three Commission Internationale de l'Elairage standard sky types. Optimum ideal dimming level was determined for each combination of room orientation, photosensor configurations and positions. In general, fully shielded photosensors achieved better control performance among other configurations used for the photosensors on the ceiling and the back wall. The effect of photosensor configurations on dimming system performance was as significant as the photosensor positions. As the penetration of daylight decreased due to the shaded area on the internal envelope, the control system performance deteriorated. The correlation between the photosensor signals and the desktop illuminance levels due to daylight was not significantly meaningful under the lighting systems. Lighting energy savings were determined for the best and good system control performance. Copyright r 2009 John Wiley & Sons, Ltd.