On the Interaction between the Depth and Elevation of External Shading Devices in Tropical Daylit Classrooms with Symmetrical Bilateral Openings

Abstract

External shading devices are an important design feature in tropical buildings, particularly for climate mitigation. However, the interaction between the depth and elevation of the shading devices and their impact on indoor daylight performance is not fully understood, especially for the case of tropical buildings with bilateral openings. This study therefore aims to evaluate the design possibilities of external shading devices with various depth and elevation in terms of daylight performance for the case of tropical school classrooms with bilateral openings in an Indonesian city. A computational simulation method using Radiance is utilized to perform annual daylight metrics calculations. Geometry, material, and simulation settings are prepared using the Ladybug tool under Grasshopper for four building orientations, namely 0°, 45°, 90°, and 135°. Sensitivity and uncertainty analyses are conducted for all design combinations. The results show that the interaction between a shading device’s depth and elevation is unique, depending on the building orientation and the availability of direct sunlight. In general, shading elevation is more influential, compared to shading depth, on the observed daylight metrics and the combined objective functions at all orientations.