Changing the direction of the luminaire: A strategy to improve lighting energy efficiency in offices

Light environment’s non-visual effects influence people’s health and work efficiency. However, considering requirements in addition to traditional visual may significantly increase lighting energy consumption. This study utilized simulation software explore saving potential of changing the direction luminaire. A model a single-person office with luminaire attached ceiling right above workstation was built ECOTECT. Vertical eye-level illuminance horizontal work-plane were calculated luminaires different luminous fluxes elevation angles from downward vertical (0°-180° at an interval 10° on both sides) using RADIANCE. Furthermore, six cases light correlated color temperatures considered. Based illuminance-versus-luminous flux coefficients obtained results, fulfill under all cases. It found that compared design facing vertically downwards, turning angle 50° reduced required by up 22.7%, which would benefit savings. Therefore, has improve efficiency when requirements.