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Daylighting performance improvements using of split louver with parametrically incremental slat angle control

Alsukkar, Muna; Hu, Mingke; Eltaweel, Ahmad; Su, Yuehong


Muna Alsukkar

Mingke Hu

Ahmad Eltaweel

Professor of Thermal Science and Building Technology


Different shading device systems and control strategies can be employed in different parts of a window system to perform different functions, particularly for fully glazed façades. A split louver with various improvements was proposed in this study as an innovative daylighting device to improve daylighting distribution and uniformity. An 8 m deep office room in Jordan was chosen for a case study, where it is south-oriented with a high window-to-wall ratio (WWR: 95%). The split louver system features two sections with different functions that can affect the quality and quantity of daylighting performance in the deep room space. Four types of parametrically controlled reflective slats, i.e., unanimous, incremental, fully parametric, and parametrically incremental, were investigated for the upper section of the split louver. While the daylighting performance of the four systems is extremely similar in terms of illuminance level but different in distribution, the parametrically incremental control is the preferred one attributed to its practicality and distribution performance. The upper section of the split louver includes blind integration, and different slat surface materials (diffuse, semi-mirrored, and mirrored) were evolved through various improvement phases. Simultaneously, the lower section of the split louver was investigated in order to adjust the overall illuminance level. The proposal of scheduled angles of split louver in both sections presented the most optimal combinations to achieve balanced daylighting levels in both the front and back of the space. This resulted in a free-glare indoor with accepted daylight uniformity levels of up to 0.60 and high percentage coverage within UDI150∼750 lx for most of the working hours throughout the year are realized (between 90% and 100% at noontime and no less than 50% along the rest of the working hours).


Alsukkar, M., Hu, M., Eltaweel, A., & Su, Y. (2022). Daylighting performance improvements using of split louver with parametrically incremental slat angle control. Energy and Buildings, 274, Article 112444.

Journal Article Type Article
Acceptance Date Aug 30, 2022
Online Publication Date Sep 7, 2022
Publication Date Nov 1, 2022
Deposit Date Sep 9, 2022
Publicly Available Date Sep 8, 2023
Journal Energy and Buildings
Print ISSN 0378-7788
Electronic ISSN 1872-6178
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 274
Article Number 112444
Keywords Electrical and Electronic Engineering; Mechanical Engineering; Building and Construction; Civil and Structural Engineering
Public URL
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Additional Information This article is maintained by: Elsevier; Article Title: Daylighting performance improvements using of split louver with parametrically incremental slat angle control; Journal Title: Energy and Buildings; CrossRef DOI link to publisher maintained version:;