| Keywords |
Control performance ; Daylight dimming system ; Lightshelf ; Office space ; Photosensor ; Sky ; Lighting energy |
| Abstract |
This study examines control performance of daylight dimming systems for lightshelf conditions applied to a small office space. Computer simulations using Lightscape software was performed for lightshelf and photosensor configurations through a year under various daylight conditions. Results imply that dimming controls for the space with lightshelves in June under clear sky was superior to those without lightshleves. In December, the dimming control failed to keep target illuminance. Under overcast sky, the dimming control was not successful to save lighting energy due to insufficient daylight. Photosensors with noshielding kept the lighting control effective. Strong linear relationships existed between desktop and photosensor illuminance under all daylight and lightshelf conditions. Effective lighting energy savings was achieved under clear and partly cloudy sky conditions and insignificant difference was noticed between them. Clear sky achieved minimum 50% of lighting energy savings, but overcast sky achieved at least 25.6% due to insufficient daylight. |