Investigating perforated egg crates as dynamic shading systems for open-plan offices in tropical climates

Abstract

This study explores the use of perforated egg crates as a dynamic shading system to improve daylight quality by achieving better uniformity in open-plan offices. Glazed curtain walls, although a popular choice in modern open-plan offices, can cause problems especially in tropical climates, such as glare and heat particularly near the windows. As egg crates (EC) generally perform better as shading devices than plain horizontal or vertical systems, this study simulated three different combinations of perforated, solid, overlapping and non-overlapping egg crate models for an existing open-plan office building in Indonesia. Daylight measurements of the existing horizontal shading device without any egg crate (NO-EC) were first recorded. Subsequent simulations of non-overlapping perforated (EC-NP) egg crate models with different blade widths and blade rotation angles in accordance with the sun elevation angles on specified working hours were performed. Similar simulations were then performed for two combinations: other combinations of overlapping solid (EC-OS) and overlapping perforated (EC-OP) egg crate models. Finally, a full-scale site mock-up of the EC-NP and NO-EC were tested under real-life climatic conditions. Results show that EC-NP provides better uniformity than the other two combinations, which is within the range of 0.59–0.99. This is due to the deeper penetration of daylight achieved by the overlapping placement of the horizontal blades in front of vertical blades, while keeping the building envelope shaded.