Daylight in atrium buildings: Geometric shape and vertical sky components

Abstract

This study investigated the impact of well geometry on vertical sky components in atria with square and rectangular forms under a CIE standard overcast sky. By comparing scale model measurements and analytical theory the vertical sky components, calculated using Radiance, were validated. More simulated data of vertical sky components for a very wide range of atrium geometries are given. From the results the attenuation of the vertical sky component on the wall of a square atrium is explained and some empirical functions are derived. In addition, the results from atrium models with rectangular floor plans show the relationships between the vertical sky component and the plan aspect ratio. Some guidelines for design are presented.