Abstract:
The objective of this research is to develop an energy conservation index for artificial lighting in buildings. The methodology includes (1) studies of articial lighting systems and equipments, (2) studies of interior designs for maximum uses of artificial lighting systems, (3) studies of influences of high-performance artificial lighting systems on building occupants. The results indicated that (1) using high-performance lighting systems and equipments (with interior surface reflections neglected) can help reducing lighting energy consumption t the level of 1.23 watt./m2/100 lux. (2) In the study of interior designs for improving lighting performance using scale models, it was found that light-color surfaces with a surface reflection of 0,84 have a 27.4% increase of interior illuminance level as compared to dark-color surfaces with 0.06 light reflection, causing a decrease of lighting energy consumption to 0.97 watt/m2/100 lux. Additionally, at every 10% increase of interior surface reflection, an energy consumption can be reduced by 0.03 watt/m2/100 lux. (3) Various interior surface colors also lead to different light reflections, thus lighting energy consumption. In terms of visual comfort, it was found that the contrast ratio between task (working plane) and surrounding surface should not exceed 10:1, whereas the ratio of luminance level between a working plane and room surrounding surfaces should not exceed than 3:1. In conclusion, high-performance lighting systems without the influence of reflecting surface, energy consumption for lighting is 1.23 watt/m2/100 lux while high performance lighting system with high reflectance surface. Energy consumption can be reduced to 0.97 watt/m/2/100 lux or 21%. The increase of every 10% of reflecting in the interior can reduce energy consumption of 0.03 watt/m/2/100 lux. Therefore, building professionals (i.e., architects and interior designers) can be an important role on conserve energy in electric lighting systems, using high-light-reflection surfaces without compromising visual comfort of the occupants.