Indoor artificial lighting: Prediction of the circadian effects of different spectral power distributions

摘要

The study presented in this paper aims to evaluate if and how the environment affects the circadian impact of a light source by predicting circadian stimulus (CS) resulting from the exposure to different light scenes, using equations reported in studies by Rea et al. The main findings are: (1) Above 600 Ix at eye level the increase of CS is little; (2) Between 50 Ix and 200 Ix at the eye level an increase of only 50 Ix determines a significant increase of CS; (3) Light sources with correlated colour temperatures between 2900 K and 4200 K have similar impacts on the circadian system according to the calculation method used; (4) Even an almost neutral environment affects the circadian impact of a light source.