Vertical daylight level

This paper investigates the impact of well geometry and surface reflectance on vertical daylight levels in atria with square forms under a CIE standard overcast sky. By reviewing some previous investigations and comparing with scale model measurements the vertical daylight factor calculated using Radiance are validated. More simulated vertical daylight factors for a very wide range of atrium geometries and reflectances are given. From the results the attenuation and distribution of the vertical daylight levels on the wall of a square atrium with different reflectances are displayed.