Integration of horizontal light pipe and shading systems in office building in the tropics

Many high-rise office buildings in the tropics have a full-glazed façade and a deep open-plan space. Without any external shading, the office space has a non-uniform daylight distribution and glare problem. A deep open-plan space design also causes insufficient daylight levels in the area distant from the building perimeter. Previous studies about Horizontal Light Pipe (HLP) mainly focused on system improvement in capturing, transporting, and distributing daylight into deep space. Integration of HLP as a light transport system that can deliver daylight deeper into building interiors and shading systems consist of Light Shelf (LS), blinds that can redirect and reduce the excessive daylight level near the side window are proposed and studied. The research objective is to explain the daylight performance of the integration of HLP and shading systems. The research method is experimental with Radiance-based simulation as a tool. Surabaya (latitude 7.38° S and longitude 112.79° E), a typical city in the Tropics, was chosen for the simulation. Daylight level, daylight distribution, and Daylight Glare Probability (DGP) of office room with East-facing window are compared with office room with HLP and shading systems. The results showed that the integration of HLP and shading systems increased the average illuminance level in the deep area reached 135 % and reduced the average illuminance level in the area near the side window reached 55 %. HLP and shading systems also increase the daylight distribution inside space and slightly improve the DGP but still in the range of imperceptible for building users.