Daylighting performance assessment of a split louver with parametrically incremental slat angles: Effect of slat shapes and PV glass transmittance

Alsukkar, Muna; Hu, Mingke; Alkhater, Mohammed; Su, Yuehong

Abstract

Advanced shading systems, including light redirecting systems, may cause undesirable glare and affect the quality of the transmitted daylight. Therefore, it is important to integrate different building components, such as shading and glazing, to comprehensively assess daylighting performance and ensure a comfortable, luminous environment. This study proposes an advanced daylighting design based on a parametrically controlled split louver with reflective slats to redirect sunlight onto a ceiling and integrated PV glazing to control the illuminance levels. A special contoured slat design (retro shape) was evaluated and compared to different slat shapes (flat, curved, and oval) of the upper section. In addition, the effect of the PV glass transmittance (30 %, 50 %, and 70 %) on the daylighting performance was investigated. The daylight analysis was performed using Grasshopper software as a parametric tool to predict the daylighting performance through advanced dynamic metrics including Useful Daylight Illuminance (UDI), Daylight Glare Probability (DGP), and Illuminance Uniformity (Uo). It is found that the retro-shaped slat design can significantly improve the daylight distribution and level without using the common blind system for more than 90 % of the work plane area within the recommended acceptable UDI range (150 ∼ 750 lx) for a longer period of the day (including the early morning and late afternoon). Furthermore, retro-shaped slats can improve the Uo throughout the space to achieve the recommended level (0.70), while PV glazing can reduce the risk of daylight glare.

• Journal Article Type: Article
• Acceptance Date: Sep 26, 2023
• Online Publication Date: Oct 7, 2023
• Publication Date: Nov 1, 2023
• Deposit Date: Nov 21, 2023
• Publicly Available Date: Nov 21, 2023
• Journal: Solar Energy
• Print ISSN: 0038-092X
• Electronic ISSN: 1471-1257
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 264
• Article Number: 112069
• DOI: https://doi.org/10.1016/j.solener.2023.112069
• Keywords: Daylighting, Split louver, Parametric design, Slat shape, PV glass
• Public URL: https://nottingham-repository.worktribe.com/output/27589238
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0038092X2300703X?via%3Dihub
• Additional Information: This article is maintained by: Elsevier; Article Title: Daylighting performance assessment of a split louver with parametrically incremental slat angles: Effect of slat shapes and PV glass transmittance; Journal Title: Solar Energy; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.solener.2023.112069; Content Type: article; Copyright: © 2023 The Authors. Published by Elsevier Ltd on behalf of International Solar Energy Society.