Document Type : Original Article

Authors

1 Faculty of Architectural Engineering & Urbanism, Shahrood University of Technology, Shahrood, Iran.

2 Faculty of Architectural Engineering & Urbanism, Shahrood University of Technology, Shahrood, Iran

10.22044/rera.2025.15945.1409

Abstract

Daylight serves as a fundamental element in the design of sustainable buildings, significantly contributing to energy efficiency and occupant visual comfort. However, the uncontrolled penetration of natural light may result in issues such as glare and uneven daylight distribution within interior spaces. An effective approach to daylight management involves utilizing light shelves, which enhance interior daylight penetration while mitigating excessive brightness near windows. This study examines the impact of light shelves on daylight distribution improvement through simulations conducted with the Ladybug plugin within the Grasshopper plugin, integrated into the Rhino modeling software. In this process, the building model was developed under specific climatic conditions, and key light shelf parameters, including depth, angle, and surface reflectivity, were evaluated. The analysis was carried out based on illuminance metrics. Among the nine measurement points, the three terminal points in the darkest areas were selected to assess the performance of the light shelf in improving daylight distribution. This study focused on evaluating the improvement in daylight levels achieved by the selected light shelf scenario at these points and the average illuminance of the rear work surfaces that required enhancement on December 21 and June 21. As a result, the implementation of light shelves in the targeted studio contributed to a 22%–30% enhancement in daylight availability.

Keywords

Main Subjects

[1] Freewan, A.A., Maximizing the lightshelf performance by interaction between lightshelf geometries and a curved ceiling. Energy Conversion and Management, 2010. 51(8): p. 1600-1604.
[2] Freewan, A.A. and J.A. Al Dalala, Assessment of daylight performance of advanced daylighting strategies in large university classrooms; case study classrooms at JUST. Alexandria Engineering Journal, 2020. 59(2): p. 791-802.
[3] Reinhart, C.F. and D.A. Weissman, The daylit area–Correlating architectural student assessments with current and emerging daylight availability metrics. Building and environment, 2012. 50: p. 155-164.
[4] Azodo, A., Illuminance and Daylight Distribution Assessment for Learners’ Comfort and Safety in One-side-window Oriented Classroom Building. Arid Zone Journal of Engineering, Technology and Environment, 2017. 13(5): p. 567.
[5] David, A., K.A. Smet, and L. Whitehead, Methods for assessing quantity and quality of illumination. Annual Review of Vision Science, 2019. 5(1): p. 479-502.
[6] Ma’bdeh, S. and H. Matar, Designing a dynamic fenestration to improve visual performance in educational spaces using daylight. Periodicals of Engineering and Natural Sciences (PEN), 2020. 8(3): p. 1898-1910.
[7] Bakmohammadi, P. and E. Noorzai, Optimization of the design of the primary school classrooms in terms of energy and daylight performance considering occupants’ thermal and visual comfort. Energy Reports, 2020. 6: p. 1590-1607.
[8] Mangkuto, R.A., et al., Optimisation of daylight admission based on modifications of light shelf design parameters. Journal of Building Engineering, 2018. 18: p. 195-209.
[9] Iommi, M., Daylighting performances and visual comfort in Le Corbusier's architecture. The daylighting analysis of seven unrealized residential buildings. Energy and Buildings, 2019. 184: p. 242-263.
[10] Tabadkani, A., et al., Daylight in buildings and visual comfort evaluation: The advantages and limitations. 2021.
[11] Shin, J.Y., G.Y. Yun, and J.T. Kim, Evaluation of daylighting effectiveness and energy saving potentials of light-pipe systems in buildings. Indoor and built environment, 2012. 21(1): p. 129-136.
[12] Aghemo, C., A. Pellegrino, and V. LoVerso, The approach to daylighting by scale models and sun and sky simulators: A case study for different shading systems. Building and environment, 2008. 43(5): p. 917-927.
[13] Moazzeni, M.H. and Z. Ghiabaklou, Investigating the Influence of Light Shelf Geometry Parameters on Daylight Performance and Visual Comfort, a Case Study of Educational Space in Tehran, Iran. Buildings, 2016. 6(3): p. 26.
[14] Kim, K., et al., Energy-saving performance of light shelves under the application of user-awareness technology and light-dimming control. Sustainable Cities and Society, 2019. 44: p. 582-596.
[15] Lee, H., J. Seo, and S. Kim, Improvement of light-shelf performance through the use of a diffusion sheet. Building and Environment, 2018. 144: p. 248-258.
[16] Lee, H. and H. Lee, Study on the application of PV modules to curved light shelves. Building and Environment, 2022. 207: p. 108481.
[17] Kontadakis, A., et al., A review of light shelf designs for daylit environments. Sustainability 10 (1): 71. 2017.
[18] Ahmad, A., et al., Daylight availability assessment and the application of energy simulation software–A literature review. Materials Science for Energy Technologies, 2020. 3(2020): p. 679-689.
[19] Meresi, A., Evaluating daylight performance of light shelves combined with external blinds in south-facing classrooms in Athens, Greece. Energy and Buildings, 2016. 116: p. 190-205.
[20] Lim, Y.-W. and M.H. Ahmad, The effects of direct sunlight on light shelf performance under tropical sky. Indoor and Built Environment, 2015. 24(6): p. 788-802.
[21] Franco, I.M., Efficacy of light shelves: passive, dynamic and automatic devices related to light and thermal behavior. Thermal Performance of Exterior Envelopes of Whole Buildings X, 2007.
[22] Ishac, M. and W. Nadim, The Design of the Optimal Light Shelf in Educational Setting Simulation vs. Optimization in assessing daylight performance. 2016.
[23] Berardi, U. and H.K. Anaraki, The benefits of light shelves over the daylight illuminance in office buildings in Toronto. Indoor and Built environment, 2018. 27(2): p. 244-262.
[24] Xue, P., C.M. Mak, and H. Cheung, New static lightshelf system design of clerestory windows for Hong Kong. Building and Environment, 2014. 72: p. 368-376.
[25] Berardi, U. and H.K. Anaraki, Analysis of the impacts of light shelves on the useful daylight illuminance in office buildings in Toronto. Energy Procedia, 2015. 78: p. 1793-1798.
[26] Zomorodian, Z., S. Korsavi, and M. Tahsildoost, The effect of window configuration on daylight performance in classrooms: A field and simulation study. International journal of architectural engineering and urban planning, 2016. 26(1): p. 15-24.
[27] Climate.top. Climate and weather in Shahroud, Iran. 2025  May 5, 2025]; Available from: https://www.climate.top/iran/shahroud.
[28] Committee, I.O. The 5th International Conference on Computer and Knowledge Engineering. 2019  May 2025]; Available from: http://icspis.org/icspis2019/icspis.shahroodut.ac.ir.
[29] Lim, Y.-W. and C. Heng, Dynamic internal light shelf for tropical daylighting in high-rise office buildings. Building and Environment, 2016. 106: p. 155-166.
[30] Lee, H., et al., Effectiveness of a perforated light shelf for energy saving. Energy and Buildings, 2017. 144: p. 144-151.
[31] Lee, H., H.-I. Jang, and J. Seo, A preliminary study on the performance of an awning system with a built-in light shelf. Building and environment, 2018. 131: p. 255-263.
[32] Lee, H., Performance evaluation of a light shelf with a solar module based on the solar module attachment area. Building and Environment, 2019. 159: p. 106161.
[33] Teo, Y.H., et al., A simulation-aided approach in examining the viability of passive daylighting techniques on inclined windows. Energy and Buildings, 2023. 282: p. 112739.
[34] Prasertseree, L. and N. Tuaycharoen, The Effect of Curved Light Shelves, Ceiling and Window [35] Characteristics on Daylighting in Thai Classrooms. Journal of Daylighting, 2025. 12(1): p. 21-39.
[35] Bahdad, A., et al., Multi-dimensions optimization for optimum modifications of light-shelves parameters for daylighting and energy efficiency. International Journal of Environmental Science and Technology, 2022. 19(4): p. 2659-2676.
[36] Bahdad, A.A.S., S.F.S. Fadzil, and N. Taib, Optimization of daylight performance based on controllable light-shelf parameters using genetic algorithms in the tropical climate of Malaysia. Journal of Daylighting, 2020. 7(1): p. 122-136.
[37] Lee, H., S. Han, and J. Seo, Light Shelf Development Using Folding Technology and Photovoltaic Modules to Increase Energy Efficiency in Building. Buildings, 2022. 12(1): p. 81.
[38] Sabbagh, M., S. Mandourah, and R. Hareri, Light shelves optimization for daylight improvement in typical public classrooms in Saudi Arabia. Sustainability, 2022. 14(20): p. 13297.
[39] Ziaee, N. and R. Vakilinezhad, Multi-objective optimization of daylight performance and thermal comfort in classrooms with light-shelves: Case studies in Tehran and Sari, Iran. Energy and Buildings, 2022. 254: p. 111590.
[40] Hosseini, S.N. and I. SheikhAnsari, A daylight assessment on visual and nonvisual effects of light shelves: a human-centered simulation-based approach. Journal of Daylighting, 2022. 9(1): p. 28-47.
[41] Jung, S. and H. Lee, Case study for deriving appropriate light shelf specifications based on indoor space depth. Energy and Buildings, 2023. 297: p. 113450.
[42] Sharifian, Z., et al., Enhancing Daylight and Energy Efficiency in the Architecture Studio by Designing Light Shelves and Windows with Sensitivity Analysis and Optimization. International Journal of Urban Management and Energy Sustainability, 2024. 5(3): p. 146-166.
[43] Keshtkar Ghalati, A. and M. Ahmadian, Effects of window and light shelve configurations on energy consumption and daylight illuminance in classrooms. Renewable Energy Research and Applications, 2024. 5(1): p. 107-119.
[44] Zhao, X., J. Seo, and H. Lee, Performance evaluation of a light shelf with a folding reflector (LSFR) to improve daylighting performance. Building and Environment, 2024. 255: p. 111457.
[45] Carlucci, S., et al., A review of indices for assessing visual comfort with a view to their use in optimization processes to support building integrated design. Renewable and sustainable energy reviews, 2015. 47: p. 1016-1033.
[46] Kharvari, F., An empirical validation of daylighting tools: Assessing radiance parameters and simulation settings in Ladybug and Honeybee against field measurements. Solar Energy, 2020. 207: p. 1021-1036.