Using Sunlight as a Light Source in Building Cores Institutional Repository Document uri icon


  • This paper presents the lighting performance of a passive horizontal solar light pipe designed for deep floor plan buildings with open-plan configuration. The light pipe system was designed to deliver natural light at the back of deep-plan buildings (5-10 m from window wall) using an optimized geometry and high reflective materials. The current light pipe system was developed for latitude 30.6°N in a predominantly sunny and clear sky location. A 360° rotating experimental room was built to test the light pipe performance at different orientations. The experimental room represents a section of a deep open plan office space of 3.6 m high, 6.1 m wide, 9.1 m long, with an area of 56 m2. Preliminary results of photometric measurements in a South-facing orientation have shown that on clear and partly cloudy days (global horizontal illuminance GH, ranging 20,000-120,000 lux), the light pipe can provide at 8 m from the perimeter, between 300 to 2,500 lux for about nine hours (9:00 am-6:00 pm). The highest illuminance values (above 1,000 lux) are achieved consistently between 10:30 am and 4:30 pm under clear sky conditions. Natural light is evenly distributed over the workplane; the sidelight window illuminates the front of the room and the light pipe system the back.

author list (cited authors)

  • Beltran, L.

publication date

  • June 2017