The assessment of vertical daylight factors across the walls of atrium buildings, Part 2: Rectangular atria

This study investigated the impact of well geometry and surface reflectance on
vertical daylight factors on the walls of rectangular atria under a CIE standard
overcast sky. The vertical daylight factors predicted using the modelling software
Radiance were validated by artificial sky scale model measurements. More
simulated data of vertical daylight factors for a very wide range of rectangular
atrium geometries and surface reflectances are presented. From the results the
variations of the vertical daylight factor on the walls of rectangular atria were
assessed and some empirical functions were derived. Initial guidelines for
supporting design are presented.