The assessment of advanced daylighting systems in multi-story office buildings using a dynamic method

The performances of light shelf systems are evaluated in the context of various interior configurations typical of multistory office buildings by using CBDM (climate-based daylight modeling). A physical scale model of one of the light shelf systems is tested in the first phase under real sky conditions in Raleigh, North Carolina, USA. The data collected from the experiments are used to validate the simulations by a computer-based dynamic daylighting research tool - DAYSIM which is based on the concept of CBDM (Radiance + Perez Sky Luminance Model + Daylight Coefficient). In the second phase, additional simulations utilizing the validated tool are conducted to study the effects of system geometries and interior space characteristics. Specifically, the following parameters are identified and assessed: light shelf length, ceiling height, and interior configurations typical of North American office building settings. The findings have displayed the impact of various system parameters and interior design approaches on daylighting performances. The limitations of the study include possible errors in both computational simulations and the physical testing, and errors caused by the process of generating the sky models from solar radiation data for DAYSIM.