DAYLIGHT ANALYSIS IN CENTRAL ATRIUM BUILDINGS WITH MONITOR VS. SKYLIGHT ROOF APERTURES

摘要

This research is focused on daylight assessment in office buildings with central atrium comparing a monitor versus a skylight roof design. The goal is to optimize the design proportions of a central atrium building for architects to improve their atrium design under a mostly clear sky condition such as Raleigh, NC. Further research can compare the results in other atrium types under different sky conditions. This paper is focused on the central atrium, since the central type is observed as the most prevalent one among the built atrium buildings. In order to evaluate daylight, this paper employs spatial Daylight Autonomy (sDA) and Annual Solar Exposure (ASE) as climate-based metrics to compare results of central atria with different roof designs. Building on the foundations of Cartwright Sizing rule, this research measures daylight performance of an atrium based on its geometry by using the Well Index (WI) to quantify the proportion of an atrium. This study, as a result, questions the relation between daylight performance and atrium Well Index in central atrium buildings using monitor versus skylight roof apertures. This comparison requires controlling for monitor roof height to prevent its impact on daylight changes. This paper applies simulation methodology, using the latest version of DIVA for Rhino 2.1.1.1 simulation tool. Having controlled for climate, material reflectance, transmittance and monitor glazing height, the compared results demonstrated higher daylight performance for monitor roof with Well Index of 1 in Raleigh, NC. Skylight roof design does not provide the adjacent space of an atrium with comfortable light, due to the potential risk of excessive sunlight penetration.