Effects of surface reflectance and lighting design strategies on energy consumption and visual comfort

Globally, artificial lighting accounts for a considerable part of electrical energy consumption in buildings. Hence, there is a need to design appropriate lighting scenarios for buildings in a way to reduce energy while meeting visual comfort requirements. This research aims to investigate the effects of applying different design strategies on lighting energy use and visual comfort level. Surface finishing reflectance, type, number and mounting height of luminaires are variables in the study. Lighting design software DIALux evo 7.0 provides simulations of a real scale room according to different scenarios whose models were calibrated and validated using experimental field data. The findings indicate that the type of luminaire is the most decisive parameter in quantity and quality of light in an indoor environment. However, increasing the indoor surface reflectance plays a key role in improving energy efficiency and visual comfort. The results show the possibility of electrical energy savings up to 45% by increasing surface reflectance properties. Finally, this paper stresses that there is no single design solution to guarantee both low energy demand and high visual quality, therefore integrating different strategies based on the type of task and the occupant’s activities is highly recommended.