Designing an integrated daylighting system for deep-plan spaces in Malaysian low-rise buildings

Daylighting technologies have been developed recently to harness solar energy, and eventually, meet the goals of sustainable development. However, the use of natural light in the tropics is challenging. Many factors limit the efficiency of solar energy because of the intensity of solar irradiance and the inconstancy of sky conditions in this region. This research aims to design and evaluate an integrated daylighting system for enclosed spaces without access to daylight from side openings. The proposed system eliminates the requirements for electrical lighting during daytime. The new design combines three components, namely, roof light, dynamic shading, and fiber optic daylighting system, in one integrated platform. The methodology was based on a quantitative approach that used empirical experiments in an actual-sized room. Two stations were set up outside and inside the test cell for data collection. The study used a data acquisition system with nine calibrated sensors to record the performance of the integrated daylighting system. The readings indicated the capability of the system to control natural light from 8:00 to 18:00, even during peak hours. Results showed that the proposed system utilized and boosted the efficiency of the individual components, and the fiber optic daylighting system delivered sufficient level of natural light within the range of 300-680 lx, at an average of 492 lx, with functionality ranging from 44% to 54%. In addition, the skylights were controlled with a dynamic shading system and delivered a maximum reading below 2000 lx during peak times, at an average of 350 lx, with functionality between 46% and 56% under the intermediate sky condition. The integrated daylighting system delivered uniform illuminance when solar irradiance was above 500 W/m2.