Validation of a lighting simulation program under real sky conditions

Abstract

The illuminance predictions from the lighting simulation program RADIANCE are compared with measurements taken in full-scale experimental rooms under real sky conditions for both overcast and clear skies. Results are presented for clear glazing and two types of light shelf. The model sky description is based on the real sky luminance distribution measured by a sky luminance mapping instrument. The sky luminance and room illuminance measurements are simultaneous allowing an extremely accurate representation of the real conditions in the model. Model representation of the measured sky brightness distribution is described.