Abstract
Abstract The purpose of lighting is to provide a suitable illumination, color temperature and lighting way that can satisfy the user’s needs in the physiology and psychology in a limit space. For reading actions, showed by related studies, the best illumination value is between 350 and 750 lux with a color temperature ranges from 3300°K to 5000°K under commercial lighting. In this study, we discuss how the illumination conditions included RGB LEDs’ high color rendering property, different color temperature and illumination values affects the psychology of reader in an office. The methodology of this study is based on semantic differential method using two independent variables which are color temperature (2800°K~6000°K) and illumination (300 lux ~750 lux) to build the variable lighting surroundings. The goal of the lighting experiment is to establish a scientific way to obtain LED lighting conditions which are suitable for office reading through a questionnaire survey proposed by this study. The results showed that the best lighting surrounding for whole experimental subjects is 4800°K/750lux. The detail results can be categorized into three groups: sex, age and education. The female subjects are prefer to 4400°K/750lux and the male ones are 4800°K/750lux. The 21~30, 31~40 and 41~50 years old subjects are prefer to 4000°K/500lux, 4800°K/750lux and 4800°K/750lux separately. In education group, the preferences for senior high school, college, university and graduated school are 4800°K/750lux, 4400°K/750lux, 4800°K/750lux and 5200°K/750lux separately. Comprehensively evaluating the results motioned above, the proper lighting-condition preferences for subjects are the surrounding color temperature with 4000°K ~ 5200°K and the luminance with 500lux ~750lux. The best one of these lighting conditions is 4800°K/750lux。 For the whole subjects in the best lighting condition, the psycology associated feelings of space situation are to the extent to which the “very bright” and the “little graceful” as the highest. The psycology described feelings of space are to the extent to which the “little excited” and the “little confortable”as the highest. The psycology reaction feelings of space are to the extent to which the “common variable” as the highest. These results showed by this paper can be provided as the important designing references for RGB LEDs lighting design industries.