Toplighting for the tropics Conference Paper uri icon


  • This paper presents the findings of a study that investigates the daylight performance of traditional and innovative toplighting systems to maximize the energy savings by offsetting the electric lighting and air conditioning requirements during peak hours. This study also includes the daylight distribution of different systems' spacing and their effects in the energy consumption of the proposed toplighting systems. The toplighting systems were designed for Lima, Peru (latitude 12°S). The studied toplighting systems include skylights with diffusing glazing; clerestories and roof monitors with external shading devices; and skylights with splay wells, reflectors and diffusers beneath aperture. The RADIANCE ray-tracing lighting software and the EnergyPlus energy analysis computer program were used to model, simulate and analyse the daylight and thermal performance of the different toplighting systems. Results showed that roof monitors with North- and South-facing glazing, achieved the most uniform and highest illuminance levels. The skylights with splay wells and reflectors beneath aperture achieved the most efficient overall performance: even illumination (∼500 lux), reduced glare, and low summer solar heat gains. Results confirmed that toplighting systems with good solar control and reflective surfaces can save energy by providing adequate daylight illumination in buildings so that electric lights can be turned off during peak hours.

author list (cited authors)

  • Beltran, L. O.

publication date

  • December 2005