Global energy savings in office buildings by the use of daylighting.

Outlines a study carried out in order to assess the impact of lighting energy savings on global energy consumption for office buildings. It is the result of combining both daylighting and thermal aspects in an integrated approach, and the present article concentrates on the simulation results. A modelling exercise was carried out for several facade configurations, for the four main orientations and three combinations of internal wall reflection coefficients. To perform the simulations, a daylighting simulation tool (ADELINE) was coupled with a dynamic thermal simulation software (TRNSYS). In this way the main parameters were determined that influence lighting consumption. It was found that daylighting can reduce artificial lighting consumption from 50% to 80%. States that in turn the global primary energy saving coming not only from the reduction of the lighting consumption but also from the reduction of lighting internal loads could reach 40%, for a type of glazing typically used in office buildings.