Investigating the effect of well geometry on the daylight performance in the adjoining spaces of vertical top-lit atrium buildings

Abstract

This study investigated the impact of well geometry on the amount of daylight availability in the adjoining spaces around atria with vertical top-lit forms under overcast sky condition in Malaysia. The daylight levels in the central south office rooms were derived from scale model measurements, and predictions from the lighting simulation program Radiance in Integrated Environmental Solution <Virtual Environment>. A comparison of measured data and simulations has validated Radiance simulations of atrium daylighting. The simulations show generally good agreement with physical model measurements. More simulated data of average daylight factor for a very wide range of atrium geometries are given. Findings of this research develop an atrium with optimum geometric proportions to create office spaces with enough potential for daylight utilisation. It demonstrates that a model of atrium with atrium's plan aspect ratio 1/3, atrium's section aspect ratio 1, and 3/8 atrium clerestory to atrium height is the most proper model of atrium for providing the sufficient daylight in the adjacent spaces of vertical top-lit atrium. This research will present a demonstration and general guide for the designers to predict daylighting performance of an atrium building in the tropical climate regions.