| Title |
Analyses on Daylight Variations for Optimum Controls of Daylight Dimming Systems in a Small Office |
| Authors |
윤연주(Younju Yoon) ; 백용규(Yong-Kyu Baik) ; 김수영(Sooyoung Kim) |
| DOI |
http://dx.doi.org/10.6110/KJACR.2012.24.5.433 |
| Keywords |
광센서 신호 ; 조도변동 ; 디밍제어 시스템 ; 천공비율 ; 수직조도 Photosensor signal ; Illuminance fluctuation ; Dimming control system ; Sky ratio ; Vertical illuminance |
| Abstract |
The influence of outdoor sky conditions on photosensor signals were examined to determine an appropriate index that is effectively used for optimum illuminance fluctuation when a daylight dimming system is used for a small office. Field measurements were conducted under various sky conditions. Results indicate that the outdoor global and vertical illuminance fluctuated within narrow ranges under clear and overcast sky conditions. The fluctuation of sky ratio under partly-cloudy sky caused wide ranges of illumnance fluctuation. A partially-shielded photosensor at backwall produced 56% of light output from fixtures controlled by a photosensor at ceiling. This implies that the photosensor at backwall does not always guarantee target illuminance due to the less output. The fluctuation of light output from fixtures were insignificant under clear and overcast sky. The fluctuation range of photosensor illuminance under partly-cloudy sky caused wide fluctuation ranges of light output. Regression result implies that the outdoor vertical illuminance was recommended for an effective index that is used for control of light output. |