The effect of atrium façade design on daylighting in atrium and its adjoining spaces

Abstract

Atrium buildings have been unsuccessful in utilizing available daylight in spaces adjoining the atria. Several studies indicate the potential to improve daylight in adjoining spaces through glazing distributions of progressive increase in the amount of openings from the upper to the lower floors in medium scale atria. The aim of this investigation was to study parametrically the effects of different glazing distributions on Daylight Factors (DFs) in the atrium and its adjoining spaces under overcast sky conditions. Using ECOTECT and RADIANCE, the objective was to provide optimum glazing ratios for a four sided, top-lit, square atrium building of WI 1.25. Three curves, each with five options of 20%, 30%, 40%, 50% and 60% openings on top floor with a progressive increase in openings and 100% opening on the ground floor were tested. The study concluded that façade compositions have almost no influence on the lower floor adjoining spaces where more daylight is typically required, but can have significant influence on the top two floors. Having very small windows on the top floor (20%) increases DFs in the adjoining spaces, however this increase is not significant and compromises light levels on the top two floors. In this study, the option of 60% opening on top floor, 79% opening on fourth floor, 92% opening on third floor, 98% opening on second floor and 100% opening on ground floor was recommended as it increased DFs on the top floors without compromising DFs on the lower floors. © 2010 WIT Press.