Adaptive Solar Control Through Rotating Louvers: A Material- Based Performance Study in Hot-Dry India

Adaptive Solar Control Through Rotating Louvers: A Material- Based Performance Study in Hot-Dry India | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Adaptive Solar Control Through Rotating Louvers: A Material- Based Performance Study in Hot-Dry India Aditya Ghadgine, Ipsitaa Priyadarsini Das This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8827751/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract India’s building sector faces a rapidly increasing cooling demand, with façades playing a decisive role in regulating solar heat gain. Static shading devices often fail to address dynamic solar exposure, particularly in hot-dry climates where west and south-west orientations receive intense cumulative radiation. Rotating louver façades, as a form of adaptive envelope technology, offer the potential to reduce cooling loads while maintaining visual comfort. This study evaluates the thermal performance of rotating louvers constructed from aluminum, timber/wood-plastic composite (WPC), and fiber-reinforced polymer (FRP) in the hot-dry context of India. A representative classroom volume (7 × 8 × 3 m, WWR 40%) was modeled and simulated using parametric environmental analysis tools like Rhino/Grasshopper with Ladybug and Honeybee plugins and EnergyPlus. Louvers were tested at 0°, 45°, and 90° across west and south-west orientations. Results indicate that rotating louvers reduce annual solar irradiance by 75–80% relative to unshaded baselines. Among materials, FRP consistently achieved the lowest average irradiance and variability, demonstrating superior thermal stability, while Timber/WPC reduced peak irradiance effectively and aluminum maintained higher minimum values, potentially aiding daylight penetration. Orientation and angle analysis revealed that SW façades perform best with shallow mid rotations (0–45°), while W façades require mid steep angles (45–90°) to control afternoon peaks. The findings provide evidence-based guidance for material and angle selection in adaptive façades, offering practitioners actionable strategies to enhance energy efficiency and occupant comfort in hot-dry Indian climates. Rotating louvers Solar control Annual irradiance Hot-dry climate India Kinetic facade Figures Figure 1 Figure 2 Figure 3 1. Introduction India's building sector represents one of the largest energy consumers in the nation, with industrial buildings accounting for 42% of total electricity consumption and the domestic sector contributing 26% as of 2023[ 1 ]. Peak electricity demand has experienced dramatic growth, rising from 148 GW in 2014 to a record 250 GW in 2024, and is projected by the International Energy Agency to continue growing at 6.3% annually through 2027 with cooling equipment alone expected to contribute one-third of peak electricity load by 2030 (potentially reaching 140 GW) [ 2 ]. This surge in cooling demand is underscored by record air conditioner sales of 14 million units in 2024, a 27% annual increase, despite less than 20% of Indian households currently owning air conditioners. Building façades play a crucial role in mediating this energy challenge by directly controlling solar heat gain and thermal comfort. In India's hot-dry climates, where high solar radiation and clear skies dominate much of the year, conventional static shading devices often fail to respond effectively to the dynamic nature of solar exposure [ 3 ]. Rotating louver façades, a subset of kinetic building envelope systems have emerged as an adaptive solution capable of dynamically regulating heat gain and glare throughout the day [ 4 ] [ 5 ]. Unlike static systems, these kinetic elements can adjust their orientation to optimize solar control while maintaining beneficial daylight admission. International research has demonstrated significant energy reduction potential for kinetic shading systems. Studies indicate that kinetic louvers can achieve energy savings ranging from 28% to 30% for heating and 28% to 33% for cooling compared to conventional systems [ 6 ] Research on kinetic facades in Chennai showed that such systems can decrease Annual Sunlight Exposure (ASE) by up to 65% while improving daylight performance [ 7 ]. Additionally, kinetic shading systems have been shown to reduce interior air temperatures by 4.0°C to 4.8°C while achieving overall energy reductions of up to 43% [ 6 ]. However, there remains a significant research gap in understanding how different louver materials influence thermal performance specifically within Indian hot-dry climates. Most existing studies have focused on geometric configurations, control strategies, or daylighting performance, with limited comparative analysis of material properties as thermal variables. Furthermore, while international research demonstrates the general effectiveness of kinetic systems, the specific performance characteristics of materials such as aluminum, timber/wood-plastic composite (WPC), and fiber-reinforced plastic (FRP) in Indian climatic conditions remain underexplored. This study aims to address these gaps by evaluating the thermal performance of rotating louver façades constructed from different materials in hot-dry Indian climates. Through simulation-based analysis of aluminum, timber/WPC, and FRP louvers across various orientations and rotation angles, the research seeks to establish comparative insights into their effectiveness in minimizing solar heat gain and reducing cooling demand, providing evidence-based recommendations for energy-efficient façade design in the Indian context. 2. Literature Review 2.1 Global Studies: Kinetic Façades and Dynamic Shading Systems The development of kinetic façades has emerged as a significant area of research in sustainable building design, with numerous international studies demonstrating their energy-saving potential. Charpentier et al. (2020) developed an occupant-centered optimization framework demonstrating that dynamic shading systems can achieve cooling energy demand reductions of 38–76% depending on orientation, with venetian-style systems performing particularly well with 68–76% reductions across different orientations [ 8 ]. Their study also showed that awning shades achieved 38–50% cooling energy reductions depending on facade orientation. Further Research indicates that kinetic louvers can achieve energy savings ranging from 28% to 30% for heating and 28% to 33% for cooling compared to conventional systems [ 6 ]. Such kinetic shading systems have also been demonstrated to reduce interior air temperatures by 4.0°C to 4.8°C while achieving overall energy reductions of up to 43% [ 6 ]. Recent systematic literature reviews highlight the growing interest in adaptive shading devices, with research focusing on optimization methodologies and performance evaluation frameworks [ 9 ] .However, barriers to widespread implementation remain, including high initial costs, complex control systems, and lack of awareness among building professionals. 2.2 Indian Studies: Passive Cooling and Movable Shading Research Research on dynamic shading in the Indian context remains limited compared to international studies. Studies on kinetic facades in Chennai showed that such systems can decrease Annual Sunlight Exposure (ASE) by up to 65% while improving daylight performance [ 7 ]. This research also demonstrated that kinetic systems could achieve significant improvements in thermal comfort in hot-humid climates. Indian traditional architecture has long incorporated passive cooling strategies appropriate to hot-dry climates. Historical buildings were designed with locally available materials and construction techniques optimized for climatic conditions [ 10 ]. However, modern construction practices have largely abandoned these strategies in favor of Western-style glass-concrete architecture, exacerbating urban heat island effects and increasing dependence on mechanical cooling. Recent studies have identified significant barriers to adaptive facade adoption in Indian buildings, noting that adaptive facades are underutilized due to high initial costs and low awareness, despite their proven effectiveness in international contexts [ 9 ]. 2.3 Synthesis and Research Gaps The literature reveals a clear progression in understanding kinetic façade performance globally, but significant gaps remain, particularly in the Indian context. While international studies have established the substantial energy-saving potential of kinetic systems (with reported energy reductions ranging from 28% to 76%), most research focuses on geometric optimization and control strategies rather than material-specific performance evaluation. Two primary research gaps have been identified: Limited Material Comparison Studies : Most existing research has focused on single materials or geometric variations, with insufficient comparative analysis of thermal performance of different louver materials. Insufficient Climate-Specific Performance Data : Although international studies provide valuable insights, the unique characteristics of Indian hot-dry climates including extreme temperatures (40–45°C), high solar radiation (5.5–6.5 kWh/m²/day), and low humidity require localized performance evaluation. From this review, it is evident that while kinetic facade technology shows substantial promise for energy savings in hot climates, there remains a critical need for systematic evaluation of material-specific performance of rotating louver systems in Indian hot-dry climatic conditions. 3. Materials and Methods 3.1 Research Approach This study employs a simulation-based parametric approach to evaluate the thermal performance of rotating louver façades. The research framework comprises three sequential phases (Figure 1): Phase 1: Context Analysis and Parameter Definition · Comprehensive review of global and Indian literature on kinetic façades · Identification of key performance metrics: solar irradiance, spatial uniformity, and peak load mitigation · Selection of three representative façade materials (Aluminum, Timber/WPC, FRP) based on prevalence in Indian construction Phase 2: Parametric Modeling and Simulation · Development of a parametric building model in Rhino/Grasshopper · Integration of rotating louver geometry with angular control logic (0°, 45°, 90°) · Annual thermal simulations using Ladybug/Honeybee plugins linking Radiance for irradiance mapping and EnergyPlus for energy validation Phase 3: Performance Analysis and Synthesis · Comparative analysis of simulation outputs across materials, orientations, and configurations · Derivation of evidence-based insights on thermal performance · Formulation of design guidelines for rotating louver façades in hot-dry Indian climates Figure 1: Methodology 3.2 Material Selection Three materials representing the spectrum of contemporary façade construction in India were selected (Table 1): · Aluminum: Widely used in commercial applications for its high structural strength, reflective properties, and minimal maintenance requirements, making it a benchmark material for comparison.[16] · Timber/Wood- Plastic Composite (WPC): Represents sustainable material trends in residential and institutional projects, offering moderate thermal resistance and lower embodied energy compared to metals.[17] · Fiber- Reinforced Polymer (FRP): An emerging high-performance material combining low thermal conductivity with excellent durability and corrosion resistance, suitable for India's diverse climatic conditions. Table 1: Case studies of buildings in India with louver façades, detailing material use and climatic context. Project Location Material Climate References Lilavati Lalbhai Library, CEPT University Ahmedabad, Gujarat Timber Hot And Dry [11] B-Safal Corporate House (HCP) Ahmedabad, Gujarat Timber Hot And Dry [12] Safal Profitaire (HCP) Ahmedabad, Gujarat FRP Hot And Dry [13] Keshav Lakshmi Office/House Ahmedabad, Gujarat Corten steel Hot And Dry [14] Script – Godrej Flagship Store Bengaluru, Karnataka Aluminium Temperate [15] 3.3 Simulation Model Development 3.3.1. Representative Test volume Classrooms typically exhibit high cooling demand due to dense occupancy and prolonged usage during the day, making them critical zones for thermal comfort interventions [18]. Representative classroom dimensions in India generally range around 7 m × 8 m (Figure 2), aligning with standard space planning guidelines by the Central Board of Secondary Education, which emphasizes functionality and occupant comfort [19], The National Building Code of India further recommends a window-to-wall ratio (WWR) of 30-40% for classrooms to optimize daylighting while controlling solar heat gain [20]. For this study, a classroom volume of 7 m × 8 m × 3 m with WWR 40% was selected. Figure 2. Representative classroom volume (7 m × 8 m × 3 m, WWR 40%) showing studied façade orientations: West and South-West. 3.3.2. Orientation and Climate Context Two critical orientations were analyzed based on their solar exposure characteristics in hot-dry climates [3]: · West-facing façade: Subject to intense afternoon solar radiation coinciding with peak outdoor temperatures. · South-west-facing façade: Receives oblique afternoon radiation causing cumulative thermal stress. 3.3.3. Louver Configuration · Geometry: Vertical louvers with 150 mm width, 50% overlap ratio. · Rotation angles: 0° (closed), 45° (mid-rotation), 90° (open). · Control logic: Fixed-angle analysis (representing seasonally adjustable systems). The study tested rotating louvers at three fixed angles representing different operational modes where were selected based on prior research indicating their relevance for solar control in kinetic façade systems [4]. 4. Results 4.1 Annual Irradiance Distribution Annual irradiance is the measure of total solar energy received per unit area over the course of a year, expressed in kilowatt-hours per square meter per year (kWh/m²/yr). It accounts for direct, diffuse, and reflected solar radiation impacting the surface and is critical for evaluating solar heat gain through façades. The results of the simulations were first analyzed in terms of annual cumulative irradiance (kWh/m²/year) across the sensor grid for both South-West (SW) and West (W) façades (Table 2). The four key indicators considered were average irradiance, maximum, minimum, and standard deviation. · The baseline (no louvers) case recorded the highest values, with SW orientation reaching an average of 19.25 kWh/m²/year and W orientation 17.54 kWh/m²/year, confirming their vulnerability to solar heat gain. · Across all louver configurations, average irradiance dropped by ~75-80% compared to baseline, demonstrating the effectiveness of rotating louvers in reducing long-term solar loads. · Peak irradiance (maximum values) was reduced by 9-11% relative to baseline, indicating significant mitigation of overheating and glare potential. · Minimum irradiance values approached near-zero in shaded regions, particularly for louvers at 90°, reflecting effective solar blockage. · Standard deviation decreased by ~70-75% with louvers, showing improved uniformity of heat distribution across the floor plate. Table 2. Annual irradiance metrics for baseline and louver-shaded conditions Orientation Case Avg Irr Max Irr Min Irr Std Dev SW Baseline 19.25 482.6 4.91 179.52 With Louvers 3.9–13 427–490 ~1–3 46–119 W Baseline 17.54 499.55 54.94 161.86 With Louvers 3.8–10 447–495 2.8–54 44–105 Figure 3. This figure shows the heat map with and without louvers 4.2 Comparative Material Performance The performance of Aluminum, Timber/WPC, and FRP louvers was evaluated under identical orientation (SW, W) and angle conditions (0°, 45°, 90°). Detailed simulation results are provided in Table 3, with a summary of top-performing materials for each metric in Table 4. Table 3. Performance data for Aluminum, Timber and FRP louvers across orientations and angles Materials Orientation Angle Avr_irr Max_irr Min_irr Std_dev Aluminium SW 0 3.941246 427.0947 1.059378 113.8845 Timber SW 0 3.940704 428.0354 1.015845 46.75043 FRP SW 0 3.941649 441.6629 27.15395 46.91584 Aluminium SW 45 8.631953 450.0145 2.121687 88.66184 Timber SW 45 8.970911 443.2767 1.719883 92.17953 FRP SW 45 8.598884 439.2243 1.708988 88.03549 Aluminium SW 90 12.42626 447.9433 3.190506 113.973 Timber SW 90 13.04564 490.4063 3.191299 119.2557 FRP SW 90 12.45797 468.1222 3.392916 113.7434 Aluminium W 0 3.885004 447.6684 28.53459 44.08649 Timber W 0 3.892239 455.8889 26.23902 43.80643 FRP W 0 3.876472 467.1193 51.08895 43.80985 Aluminium W 45 8.767956 474.4157 19.96184 87.99009 Timber W 45 9.115742 480.3314 20.27269 92.27715 FRP W 45 8.729333 453.1241 18.90655 87.92738 Aluminium W 90 10.22143 461.4432 2.978778 99.89105 Timber W 90 10.86819 476.271 3.122685 105.3714 FRP W 90 10.20192 495.3129 2.810117 99.16431 · Average Irradiance ( Avr_irr) : FRP consistently recorded the lowest average irradiance across all scenarios, typically 2–3% lower than Aluminum and Timber/WPC, indicating superior long-term heat gain control. · Maximum Irradiance ( Max_irr) : Timber and FRP showed slightly lower peaks (~9-11% reduction) compared to Aluminum, which retained higher localized hot spots due to reflectivity. · Minimum Irradiance ( MIN_irr) : Aluminum recorded higher baseline values (~15-20% above Timber/FRP), suggesting it maintains residual solar penetration even at steeper angles. · Standard Deviation ( Std_dev) : FRP and Timber produced the lowest variation, reducing spatial fluctuations in heat gain by 74% compared to baseline. Aluminum,while effective overall, showed higher variability. Table 4. Best-performing material for each performance metric Orientation Angle Best Avg Irr Lowest Max Irr Best Min Irr Lowest StdDev SW 0° FRP Timber Aluminium Timber 45° FRP FRP Aluminium FRP 90° FRP Timber Aluminium FRP W 0° FRP Timber Aluminium FRP 45° FRP FRP Aluminium FRP 4.3 Orientation and Angle Sensitivity 4.3.1 Orientation Sensitivity · South-West (SW): Experienced higher cumulative solar exposure (baseline avg: 19.25 kWh/m²/yr). Louvers performed optimally at shallow-to-mid angles (0°-45°), balancing shading with useful daylight admission. · West (W): Subjected to sharper afternoon peaks (baseline max: ~500 W/m²). Effective solar control required steeper angles (45°-90°), reducing peak irradiance by 9-11%. 4.3.2 Angle Sensitivity · 0° (Closed/Steep): Achieved maximum reduction in average and peak irradiance but resulted in very low minimum irradiance (~1-3 W/m²), potentially causing underlit interiors. · 45° (Mid-rotation): Provided the most balanced performance significant reduction in average irradiance, controlled peaks, and moderate daylight penetration making it suitable for both SW and W orientations. · 90° (Open/Shallow): Offered limited solar control, retaining higher residual heat gain while allowing greater daylight penetration. 5. Discussion 5.1 Effectiveness of Rotating Louvers The results confirm that rotating louvers significantly reduce annual solar irradiance by approximately 75–80% compared to unshaded baselines. This aligns with prior research indicating that kinetic façades can lower cooling energy loads by 30–50% [ 6 ]. The substantial reduction underscores the potential of rotating louvers as a primary passive cooling strategy in hot–dry Indian climates, where managing solar heat gain is critical for maintaining indoor thermal comfort. 5.2 Material Performance FRP louvers exhibited the best overall thermal performance, consistently achieving the lowest average and peak irradiance values with reduced spatial variability. This makes FRP the most thermally stable option under the conditions studied. Timber/WPC louvers performed effectively in reducing peak irradiance but showed slightly higher variability in shading uniformity across the façade. Aluminum louvers, while reducing peak irradiance less than the other materials, maintained higher minimum irradiance levels. This characteristic could support greater daylight penetration but may also contribute to increased overall solar heat gain. These findings highlight that material properties not just geometry or angle significantly influence shading performance, an aspect that has been underrepresented in prior louver studies (22). 5.3 Orientation and Angle Impacts The southwest (SW) façade, exposed to cumulative solar loads throughout the day, benefited most from shallow to mid-range louver angles (0° to 45°) for optimal shading efficiency. The west-facing façade, which faces high-intensity afternoon sunlight, requires steeper louver angles (45° to 90°) to effectively mitigate peak solar radiation, corroborating findings in Indian climate resilience research and IS 875 (23) guidelines. This orientation/angle sensitivity affirms the need for adaptive shading strategies tailored to façade orientation in cooling-dominated climates. 5.4 Design Implications For educational and institutional buildings in hot-dry climates, FRP louvers at a 45° rotation represent an optimal balance of solar protection and material durability. Aluminum louvers can be preferable when daylighting remains a priority despite higher solar gains. Timber/WPC offers a mid-range option with good shading and sustainability tradeoffs, though considerations for maintenance and long-term performance in harsh environments are required. 5.5 Contribution to Literature This study advances façade research by incorporating a detailed, comparative assessment of material-specific irradiance effects and spatial uniformity (standard deviation). It highlights thermal stability as a key performance metric alongside geometric and operational variables. The findings provide evidence-based guidance for selecting louver materials and configuring rotation angles to optimize solar control in hot-dry Indian climates. 6. Conclusions This study evaluated the thermal performance of rotating louver façades in a hot-dry climate through simulation-based analysis of three materials like aluminum, timber/WPC, and FRP, across rotation angles of 0°, 45°, and 90° on west and southwest orientations. The findings offer evidence-based insights for sustainable façade design in Indian contexts: Performance Effectiveness : Rotating louvers achieved a substantial 75–80% reduction in annual solar irradiance compared to unshaded baselines, demonstrating their efficacy as a primary passive cooling strategy for buildings in hot dry climates. Material-Specific Insights : FRP louvers consistently outperformed other materials, delivering the lowest average irradiance (8.60-12.46 kWh/m²/yr) and minimal spatial variation, indicating superior thermal stability. Timber/WPC proved effective in peak load reduction but exhibited moderate variability, while aluminum maintained higher minimum irradiance levels, potentially supporting daylighting needs at the expense of thermal performance. Orientation and Angle Optimization : Southwest façades benefit most from shallow to mid-range angles (0°-45°) to address cumulative solar exposure, whereas west façades require steeper configurations (45°-90°) to mitigate intense afternoon solar loads. The 45° rotation angle emerges as the optimal compromise, balancing average reduction, peak control, and uniform distribution across both orientations. Design Recommendations : For educational and institutional buildings in hot dry India, FRP louvers at 45° rotation provide the most effective solar control with consistent thermal performance, making them suitable for large-scale implementation in climate-responsive architecture. 6.1 Future Scope To build upon this work, the following research directions are recommended: Climate Zone Extension : Expanding the analysis to other Indian climate zones composite, warm-humid, and temperate will validate the broader applicability of these findings and enable region-specific design guidelines. Integrated Performance Metrics : Future research should incorporate daylight autonomy, glare indices, and occupant thermal comfort metrics to provide holistic façade performance evaluation beyond solar heat gain reduction. Real-World Validation : Developing physical prototypes and field testing will validate simulation predictions and inform practical implementation strategies, including material durability and maintenance considerations. Automated Control Systems : Investigating sensor-based, real-time louver control algorithms that respond to solar conditions, indoor temperature, and occupancy patterns will advance adaptive façade technologies for Indian buildings. Economic Feasibility : Conducting lifecycle cost analysis comparing initial investment, energy savings, and maintenance costs will support widespread adoption by architects and developers in the Indian construction industry. Declarations Ethics, Consent to Participate, and Consent to Publish declarations: not applicable. Funding No funding was obtained. Author Contribution Material preparation, data collection and analysis were performed by Aditya Ghadgine and Ar. 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Thermal Environment and Energy Performance of a Typical Classroom Building in a Hot-Humid Region: A Case Study in Guangzhou, China. Geofluids. Jan. 2022;2022(1):3226001. 10.1155/2022/3226001 . Construction Requirement for a CBSE / ICSE School. Accessed: Sep. 24, 2025. [Online]. Available: https://brightoninternational.in/teachclub/infrastructure-requirement-for-a-school/ 2016 20US 1 NATIONAL BUILDING CODE OF INDIA 2016 VOLUME 1 NBC. 2016 Excerpts Relating to the needs of PWD BUREAU OF INDIAN STANDARDS. Infrastructure | Central Board of Secondary Education. Accessed: Sep. 24, 2025. [Online]. Available: https://www.cbse.gov.in/cbsenew/infra.html Liang X, Zhang H, Sun B. Parametric design of photovoltaic louver integrated shading devices for west facade windows of office buildings in central China. J Asian Archit Building Eng. 2024;24(2):924–38. 10.1080/13467581.2024.2320326 . Bureau of Indian Standards. (2015). IS 875 (Part 3): 2015 – Code of practice for design loads (other than earthquake) for buildings and structures: Part 3 – Wind loads (Second Revision). New Delhi: Bureau of Indian Standards. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8827751","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":601060003,"identity":"8af9b617-ce11-4aea-8a18-eaa471d725ae","order_by":0,"name":"Aditya Ghadgine","email":"","orcid":"","institution":"Manipal Academy of Higher Education","correspondingAuthor":false,"prefix":"","firstName":"Aditya","middleName":"","lastName":"Ghadgine","suffix":""},{"id":601060004,"identity":"1020029a-6b68-4553-8aa1-80b5d2af326e","order_by":1,"name":"Ipsitaa Priyadarsini Das","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABBElEQVRIiWNgGAWjYBACNiA+AMSMDQzMIFqCgYEdSPEQ0nIArIUtAaKFmYAWMIBo4TGA8Ahp4ZNuf3j4Qw2DbH//ma8bfu6wyONvZmB88LYNj8NkzhgcOHCMwXjGjdxtN3vPSBRLHGZgNpyLT4tEDtAvbAyJDTd4t93gbZNIbDjMwCbNi1dL+oMDB/4xJM4/f+bZzb9ALfMPM7D/xq8lweDAwTaGxA0Hcthug2zZALSFGa8WkF/O9kkYb7yRZnZbtk2i2PAwY7PknHO4tcjPbn/8oeKbjey884ef3XzbVpcnd7z54Ic3Zbi1gOIOToJAAjiO8AIJNH4CfuWjYBSMglEwEgEAIKpYd6G1zxQAAAAASUVORK5CYII=","orcid":"","institution":"Manipal Academy of Higher Education","correspondingAuthor":true,"prefix":"","firstName":"Ipsitaa","middleName":"Priyadarsini","lastName":"Das","suffix":""}],"badges":[],"createdAt":"2026-02-09 08:24:18","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8827751/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8827751/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104106256,"identity":"c7268791-cb67-4aa0-b944-16f81e1d531b","added_by":"auto","created_at":"2026-03-06 22:04:45","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":243973,"visible":true,"origin":"","legend":"\u003cp\u003eMethodology\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8827751/v1/466393bd285f346e9797fa82.png"},{"id":104106257,"identity":"0a550ace-5c46-4d38-968e-b4a798b46f5d","added_by":"auto","created_at":"2026-03-06 22:04:45","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":167868,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative classroom volume (7 m × 8 m × 3 m, WWR 40%) showing studied façade orientations:\u003c/p\u003e\n\u003cp\u003eWest and South-West.\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8827751/v1/97ed285e0b17db5a03b71b87.jpeg"},{"id":104106258,"identity":"1c3dabc5-1e5b-4bf9-8ffb-b347ea9e7a14","added_by":"auto","created_at":"2026-03-06 22:04:45","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":172712,"visible":true,"origin":"","legend":"\u003cp\u003eThis figure shows the heat map with and without louvers\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8827751/v1/409ebadcffce172f91d26bef.jpg"},{"id":108163447,"identity":"3fe3c248-5fa7-4af3-aa1f-17445f280e59","added_by":"auto","created_at":"2026-04-30 04:55:10","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":874973,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8827751/v1/c4892988-90c5-4136-855b-cdbf710e6249.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Adaptive Solar Control Through Rotating Louvers: A Material- Based Performance Study in Hot-Dry India","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eIndia's building sector represents one of the largest energy consumers in the nation, with industrial buildings accounting for 42% of total electricity consumption and the domestic sector contributing 26% as of 2023[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Peak electricity demand has experienced dramatic growth, rising from 148 GW in 2014 to a record 250 GW in 2024, and is projected by the International Energy Agency to continue growing at 6.3% annually through 2027 with cooling equipment alone expected to contribute one-third of peak electricity load by 2030 (potentially reaching 140 GW) [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. This surge in cooling demand is underscored by record air conditioner sales of 14\u0026nbsp;million units in 2024, a 27% annual increase, despite less than 20% of Indian households currently owning air conditioners.\u003c/p\u003e \u003cp\u003eBuilding fa\u0026ccedil;ades play a crucial role in mediating this energy challenge by directly controlling solar heat gain and thermal comfort. In India's hot-dry climates, where high solar radiation and clear skies dominate much of the year, conventional static shading devices often fail to respond effectively to the dynamic nature of solar exposure [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Rotating louver fa\u0026ccedil;ades, a subset of kinetic building envelope systems have emerged as an adaptive solution capable of dynamically regulating heat gain and glare throughout the day [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Unlike static systems, these kinetic elements can adjust their orientation to optimize solar control while maintaining beneficial daylight admission. International research has demonstrated significant energy reduction potential for kinetic shading systems. Studies indicate that kinetic louvers can achieve energy savings ranging from 28% to 30% for heating and 28% to 33% for cooling compared to conventional systems [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] Research on kinetic facades in Chennai showed that such systems can decrease Annual Sunlight Exposure (ASE) by up to 65% while improving daylight performance [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Additionally, kinetic shading systems have been shown to reduce interior air temperatures by 4.0\u0026deg;C to 4.8\u0026deg;C while achieving overall energy reductions of up to 43% [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. However, there remains a significant research gap in understanding how different louver materials influence thermal performance specifically within Indian hot-dry climates. Most existing studies have focused on geometric configurations, control strategies, or daylighting performance, with limited comparative analysis of material properties as thermal variables. Furthermore, while international research demonstrates the general effectiveness of kinetic systems, the specific performance characteristics of materials such as aluminum, timber/wood-plastic composite (WPC), and fiber-reinforced plastic (FRP) in Indian climatic conditions remain underexplored. This study aims to address these gaps by evaluating the thermal performance of rotating louver fa\u0026ccedil;ades constructed from different materials in hot-dry Indian climates. Through simulation-based analysis of aluminum, timber/WPC, and FRP louvers across various orientations and rotation angles, the research seeks to establish comparative insights into their effectiveness in minimizing solar heat gain and reducing cooling demand, providing evidence-based recommendations for energy-efficient fa\u0026ccedil;ade design in the Indian context.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e"},{"header":"2. Literature Review","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Global Studies: Kinetic Fa\u0026ccedil;ades and Dynamic Shading Systems\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eThe development of kinetic fa\u0026ccedil;ades has emerged as a significant area of research in sustainable building design, with numerous international studies demonstrating their energy-saving potential. Charpentier et al. (2020) developed an occupant-centered optimization framework demonstrating that dynamic shading systems can achieve cooling energy demand reductions of 38\u0026ndash;76% depending on orientation, with venetian-style systems performing particularly well with 68\u0026ndash;76% reductions across different orientations [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Their study also showed that awning shades achieved 38\u0026ndash;50% cooling energy reductions depending on facade orientation.\u003c/p\u003e \u003cp\u003eFurther Research indicates that kinetic louvers can achieve energy savings ranging from 28% to 30% for heating and 28% to 33% for cooling compared to conventional systems [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Such kinetic shading systems have also been demonstrated to reduce interior air temperatures by 4.0\u0026deg;C to 4.8\u0026deg;C while achieving overall energy reductions of up to 43% [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eRecent systematic literature reviews highlight the growing interest in adaptive shading devices, with research focusing on optimization methodologies and performance evaluation frameworks [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] .However, barriers to widespread implementation remain, including high initial costs, complex control systems, and lack of awareness among building professionals.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Indian Studies: Passive Cooling and Movable Shading Research\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eResearch on dynamic shading in the Indian context remains limited compared to international studies. Studies on kinetic facades in Chennai showed that such systems can decrease Annual Sunlight Exposure (ASE) by up to 65% while improving daylight performance [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. This research also demonstrated that kinetic systems could achieve significant improvements in thermal comfort in hot-humid climates.\u003c/p\u003e \u003cp\u003eIndian traditional architecture has long incorporated passive cooling strategies appropriate to hot-dry climates. Historical buildings were designed with locally available materials and construction techniques optimized for climatic conditions [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. However, modern construction practices have largely abandoned these strategies in favor of Western-style glass-concrete architecture, exacerbating urban heat island effects and increasing dependence on mechanical cooling.\u003c/p\u003e \u003cp\u003eRecent studies have identified significant barriers to adaptive facade adoption in Indian buildings, noting that adaptive facades are underutilized due to high initial costs and low awareness, despite their proven effectiveness in international contexts [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3 \u003cb\u003eSynthesis and Research Gaps\u003c/b\u003e\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eThe literature reveals a clear progression in understanding kinetic fa\u0026ccedil;ade performance globally, but significant gaps remain, particularly in the Indian context. While international studies have established the substantial energy-saving potential of kinetic systems (with reported energy reductions ranging from 28% to 76%), most research focuses on geometric optimization and control strategies rather than material-specific performance evaluation. Two primary research gaps have been identified:\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eLimited Material Comparison Studies\u003c/b\u003e: Most existing research has focused on single materials or geometric variations, with insufficient comparative analysis of thermal performance of different louver materials.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eInsufficient Climate-Specific Performance Data\u003c/b\u003e: Although international studies provide valuable insights, the unique characteristics of Indian hot-dry climates including extreme temperatures (40\u0026ndash;45\u0026deg;C), high solar radiation (5.5\u0026ndash;6.5 kWh/m\u0026sup2;/day), and low humidity require localized performance evaluation.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eFrom this review, it is evident that while kinetic facade technology shows substantial promise for energy savings in hot climates, there remains a critical need for systematic evaluation of material-specific performance of rotating louver systems in Indian hot-dry climatic conditions.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"3. Materials and Methods","content":"\u003cp\u003e3.1 \u003cstrong\u003eResearch Approach\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study employs a simulation-based parametric approach to evaluate the thermal performance of rotating louver fa\u0026ccedil;ades. The research framework comprises three sequential phases (Figure 1):\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePhase 1: Context Analysis and Parameter Definition\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026middot; Comprehensive review of global and Indian literature on kinetic fa\u0026ccedil;ades\u003c/p\u003e\n\u003cp\u003e\u0026middot; Identification of key performance metrics: solar irradiance, spatial uniformity, and peak load mitigation\u003c/p\u003e\n\u003cp\u003e\u0026middot; Selection of three representative fa\u0026ccedil;ade materials (Aluminum, Timber/WPC, FRP) based on prevalence in Indian construction\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePhase 2: Parametric Modeling and Simulation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026middot; Development of a parametric building model in Rhino/Grasshopper\u003c/p\u003e\n\u003cp\u003e\u0026middot; Integration of rotating louver geometry with angular control logic (0\u0026deg;, 45\u0026deg;, 90\u0026deg;)\u003c/p\u003e\n\u003cp\u003e\u0026middot; Annual thermal simulations using Ladybug/Honeybee plugins linking Radiance for irradiance mapping and EnergyPlus for energy validation\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePhase 3: Performance Analysis and Synthesis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026middot; Comparative analysis of simulation outputs across materials, orientations, and configurations\u003c/p\u003e\n\u003cp\u003e\u0026middot; Derivation of evidence-based insights on thermal performance\u003c/p\u003e\n\u003cp\u003e\u0026middot; Formulation of design guidelines for rotating louver fa\u0026ccedil;ades in hot-dry Indian climates\u003c/p\u003e\n\u003cp\u003eFigure 1: Methodology\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e3.2 \u003cstrong\u003eMaterial Selection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThree materials representing the spectrum of contemporary fa\u0026ccedil;ade construction in India were selected (Table 1):\u003c/p\u003e\n\u003cp\u003e\u0026middot; Aluminum: Widely used in commercial applications for its high structural strength, reflective properties, and minimal maintenance requirements, making it a benchmark material for comparison.[16]\u003c/p\u003e\n\u003cp\u003e\u0026middot; Timber/Wood- Plastic Composite (WPC): Represents sustainable material trends in residential and institutional projects, offering moderate thermal resistance and lower embodied energy compared to metals.[17] \u0026nbsp; \u0026nbsp; \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026middot; Fiber- Reinforced Polymer (FRP): An emerging high-performance material combining low thermal conductivity with excellent durability and corrosion resistance, suitable for India\u0026apos;s diverse climatic conditions.\u003c/p\u003e\n\u003cp\u003eTable 1: Case studies of buildings in India with louver fa\u0026ccedil;ades, detailing material use and climatic context.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eProject\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLocation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMaterial\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eClimate\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eReferences\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eLilavati Lalbhai Library, CEPT University\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eAhmedabad, Gujarat\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eTimber\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eHot And Dry\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e[11]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eB-Safal Corporate House (HCP)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eAhmedabad, Gujarat\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eTimber\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eHot And Dry\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e[12]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eSafal Profitaire (HCP)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eAhmedabad, Gujarat\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eHot And Dry\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e[13]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eKeshav Lakshmi Office/House\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eAhmedabad, Gujarat\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eCorten steel\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eHot And Dry\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e[14]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eScript \u0026ndash; Godrej Flagship Store\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eBengaluru, Karnataka\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eAluminium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eTemperate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e[15]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e3.3 Simulation Model Development\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3.1. Representative Test volume\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eClassrooms typically exhibit high cooling demand due to dense occupancy and prolonged usage during the day, making them critical zones for thermal comfort interventions [18]. Representative classroom dimensions in India generally range around 7 m \u0026times; 8 m (Figure 2), aligning with standard space planning guidelines by the Central Board of Secondary Education, which emphasizes functionality and occupant comfort [19], The National Building Code of India further recommends a window-to-wall ratio (WWR) of 30-40% for classrooms to optimize daylighting while controlling solar heat gain [20]. For this study, a classroom volume of 7 m \u0026times; 8 m \u0026times; 3 m with WWR 40% was selected.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFigure 2. Representative classroom volume (7 m \u0026times; 8 m \u0026times; 3 m, WWR 40%) showing studied fa\u0026ccedil;ade orientations:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWest and South-West.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3.2. Orientation and Climate Context\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTwo critical orientations were analyzed based on their solar exposure characteristics in hot-dry climates [3]:\u003c/p\u003e\n\u003cp\u003e\u0026middot; West-facing fa\u0026ccedil;ade: Subject to intense afternoon solar radiation coinciding with peak outdoor temperatures.\u003c/p\u003e\n\u003cp\u003e\u0026middot; South-west-facing fa\u0026ccedil;ade: Receives oblique afternoon radiation causing cumulative thermal stress.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3.3. Louver Configuration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026middot; Geometry: Vertical louvers with 150 mm width, 50% overlap ratio.\u003c/p\u003e\n\u003cp\u003e\u0026middot; Rotation angles: 0\u0026deg; (closed), 45\u0026deg; (mid-rotation), 90\u0026deg; (open).\u003c/p\u003e\n\u003cp\u003e\u0026middot; Control logic: Fixed-angle analysis (representing seasonally adjustable systems).\u003c/p\u003e\n\u003cp\u003eThe study tested rotating louvers at three fixed angles representing different operational modes where were selected based on prior research indicating their relevance for solar control in kinetic fa\u0026ccedil;ade systems [4].\u0026nbsp;\u003c/p\u003e"},{"header":"4. Results","content":"\u003cp\u003e\u003cstrong\u003e4.1 Annual Irradiance Distribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAnnual irradiance is the measure of total solar energy received per unit area over the course of a year, expressed in kilowatt-hours per square meter per year (kWh/m\u0026sup2;/yr). It accounts for direct, diffuse, and reflected solar radiation impacting the surface and is critical for evaluating solar heat gain through fa\u0026ccedil;ades. The results of the simulations were first analyzed in terms of annual cumulative irradiance (kWh/m\u0026sup2;/year) across the sensor grid for both South-West (SW) and West (W) fa\u0026ccedil;ades (Table 2). The four key indicators considered were average irradiance, maximum, minimum, and standard deviation.\u003c/p\u003e\n\u003cp\u003e\u0026middot; The baseline (no louvers) case recorded the highest values, with SW orientation reaching an average of 19.25 kWh/m\u0026sup2;/year and W orientation 17.54 kWh/m\u0026sup2;/year, confirming their vulnerability to solar heat gain.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026middot; Across all louver configurations, average irradiance dropped by ~75-80% compared to baseline, demonstrating the effectiveness of rotating louvers in reducing long-term solar loads.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026middot; Peak irradiance (maximum values) was reduced by 9-11% relative to baseline, indicating significant mitigation of overheating and glare potential.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026middot; Minimum irradiance values approached near-zero in shaded regions, particularly for louvers at 90\u0026deg;, reflecting effective solar blockage.\u003c/p\u003e\n\u003cp\u003e\u0026middot; Standard deviation decreased by ~70-75% with louvers, showing improved uniformity of heat distribution across the floor plate.\u003c/p\u003e\n\u003cp\u003eTable 2. Annual irradiance metrics for baseline and louver-shaded conditions\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eOrientation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCase\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAvg Irr\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMax Irr\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMin Irr\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eStd Dev\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003eSW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eBaseline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e19.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e482.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e179.52\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eWith Louvers\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3.9\u0026ndash;13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e427\u0026ndash;490\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e~1\u0026ndash;3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e46\u0026ndash;119\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003eW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eBaseline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e17.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e499.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e54.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e161.86\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eWith Louvers\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3.8\u0026ndash;10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e447\u0026ndash;495\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.8\u0026ndash;54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e44\u0026ndash;105\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eFigure 3. This figure shows the heat map with and without louvers\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.2 Comparative Material Performance\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe performance of Aluminum, Timber/WPC, and FRP louvers was evaluated under identical orientation (SW, W) and angle conditions (0\u0026deg;, 45\u0026deg;, 90\u0026deg;). Detailed simulation results are provided in Table 3, with a summary of top-performing materials for each metric in Table 4.\u003c/p\u003e\n\u003cp\u003eTable 3. Performance data for Aluminum, Timber and FRP louvers across orientations and angles\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eMaterials\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eOrientation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAngle\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAvr_irr\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMax_irr\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMin_irr\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eStd_dev\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eAluminium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3.941246\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e427.0947\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.059378\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e113.8845\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eTimber\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3.940704\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e428.0354\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1.015845\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e46.75043\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3.941649\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e441.6629\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e27.15395\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e46.91584\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eAluminium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8.631953\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e450.0145\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.121687\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e88.66184\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eTimber\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8.970911\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e443.2767\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1.719883\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e92.17953\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8.598884\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e439.2243\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1.708988\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e88.03549\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eAluminium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eSW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12.42626\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e447.9433\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3.190506\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e113.973\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eTimber\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eSW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e13.04564\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e490.4063\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3.191299\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e119.2557\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eSW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12.45797\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e468.1222\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3.392916\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e113.7434\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eAluminium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3.885004\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e447.6684\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e28.53459\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e44.08649\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eTimber\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3.892239\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e455.8889\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e26.23902\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e43.80643\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3.876472\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e467.1193\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e51.08895\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e43.80985\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eAluminium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8.767956\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e474.4157\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e19.96184\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e87.99009\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eTimber\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9.115742\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e480.3314\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e20.27269\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e92.27715\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8.729333\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e453.1241\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e18.90655\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e87.92738\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eAluminium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e10.22143\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e461.4432\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.978778\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e99.89105\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eTimber\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e10.86819\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e476.271\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3.122685\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e105.3714\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e10.20192\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e495.3129\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2.810117\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e99.16431\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026middot; \u003cstrong\u003eAverage Irradiance (\u003c/strong\u003e\u003cstrong\u003eAvr_irr)\u003c/strong\u003e:\u003c/p\u003e\n\u003cp\u003eFRP consistently recorded the lowest average irradiance across all scenarios, typically 2\u0026ndash;3% lower than Aluminum and Timber/WPC, indicating superior long-term heat gain control.\u003c/p\u003e\n\u003cp\u003e\u0026middot; \u003cstrong\u003eMaximum Irradiance (\u003c/strong\u003e\u003cstrong\u003eMax_irr)\u003c/strong\u003e:\u003c/p\u003e\n\u003cp\u003eTimber and FRP showed slightly lower peaks (~9-11% reduction) compared to Aluminum, which retained higher localized hot spots due to reflectivity.\u003c/p\u003e\n\u003cp\u003e\u0026middot; \u003cstrong\u003eMinimum Irradiance (\u003c/strong\u003e\u003cstrong\u003eMIN_irr)\u003c/strong\u003e:\u003c/p\u003e\n\u003cp\u003eAluminum recorded higher baseline values (~15-20% above Timber/FRP), suggesting it maintains residual solar penetration even at steeper angles.\u003c/p\u003e\n\u003cp\u003e\u0026middot; \u003cstrong\u003eStandard Deviation (\u003c/strong\u003e\u003cstrong\u003eStd_dev)\u003c/strong\u003e:\u003c/p\u003e\n\u003cp\u003eFRP and Timber produced the lowest variation, reducing spatial fluctuations in heat gain by 74% compared to baseline. Aluminum,while effective overall, showed higher variability.\u003c/p\u003e\n\u003cp\u003eTable 4. Best-performing material for each performance metric\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"650\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eOrientation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAngle\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eBest Avg Irr\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLowest Max Irr\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eBest Min Irr\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLowest StdDev\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003eSW\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0\u0026deg;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eTimber\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eAluminium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eTimber\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e45\u0026deg;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eAluminium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e90\u0026deg;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eTimber\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eAluminium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eW\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0\u0026deg;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eTimber\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eAluminium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e45\u0026deg;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eAluminium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFRP\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003e4.3 Orientation and Angle Sensitivity\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e4.3.1 \u003cstrong\u003eOrientation Sensitivity\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026middot; \u003cstrong\u003eSouth-West (SW):\u003c/strong\u003e Experienced higher cumulative solar exposure (baseline avg: 19.25 kWh/m\u0026sup2;/yr). Louvers performed optimally at shallow-to-mid angles (0\u0026deg;-45\u0026deg;), balancing shading with useful daylight admission.\u003c/p\u003e\n\u003cp\u003e\u0026middot; \u003cstrong\u003eWest (W):\u003c/strong\u003e Subjected to sharper afternoon peaks (baseline max: ~500 W/m\u0026sup2;). Effective solar control required steeper angles (45\u0026deg;-90\u0026deg;), reducing peak irradiance by 9-11%.\u003c/p\u003e\n\u003cp\u003e4.3.2 \u003cstrong\u003eAngle Sensitivity\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026middot; 0\u0026deg; (Closed/Steep): Achieved maximum reduction in average and peak irradiance but resulted in very low minimum irradiance (~1-3 W/m\u0026sup2;), potentially causing underlit interiors.\u003c/p\u003e\n\u003cp\u003e\u0026middot; 45\u0026deg; (Mid-rotation): Provided the most balanced performance significant reduction in average irradiance, controlled peaks, and moderate daylight penetration making it suitable for both SW and W orientations.\u003c/p\u003e\n\u003cp\u003e\u0026middot; 90\u0026deg; (Open/Shallow): Offered limited solar control, retaining higher residual heat gain while allowing greater daylight penetration.\u003c/p\u003e"},{"header":"5. Discussion","content":"\u003cdiv id=\"Sec20\" class=\"Section2\"\u003e \u003ch2\u003e5.1 \u003cb\u003eEffectiveness of Rotating Louvers\u003c/b\u003e\u003c/h2\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eThe results confirm that rotating louvers significantly reduce annual solar irradiance by approximately 75\u0026ndash;80% compared to unshaded baselines. This aligns with prior research indicating that kinetic fa\u0026ccedil;ades can lower cooling energy loads by 30\u0026ndash;50% [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The substantial reduction underscores the potential of rotating louvers as a primary passive cooling strategy in hot\u0026ndash;dry Indian climates, where managing solar heat gain is critical for maintaining indoor thermal comfort.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003e \u003cem\u003e5.2\u003c/em\u003e \u003cb\u003eMaterial Performance\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eFRP louvers exhibited the best overall thermal performance, consistently achieving the lowest average and peak irradiance values with reduced spatial variability. This makes FRP the most thermally stable option under the conditions studied.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eTimber/WPC louvers performed effectively in reducing peak irradiance but showed slightly higher variability in shading uniformity across the fa\u0026ccedil;ade.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eAluminum louvers, while reducing peak irradiance less than the other materials, maintained higher minimum irradiance levels. This characteristic could support greater daylight penetration but may also contribute to increased overall solar heat gain.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eThese findings highlight that material properties not just geometry or angle significantly influence shading performance, an aspect that has been underrepresented in prior louver studies (22).\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003e \u003cem\u003e5.3\u003c/em\u003e \u003cb\u003eOrientation and Angle Impacts\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eThe southwest (SW) fa\u0026ccedil;ade, exposed to cumulative solar loads throughout the day, benefited most from shallow to mid-range louver angles (0\u0026deg; to 45\u0026deg;) for optimal shading efficiency.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eThe west-facing fa\u0026ccedil;ade, which faces high-intensity afternoon sunlight, requires steeper louver angles (45\u0026deg; to 90\u0026deg;) to effectively mitigate peak solar radiation, corroborating findings in Indian climate resilience research and IS 875 (23) guidelines.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eThis orientation/angle sensitivity affirms the need for adaptive shading strategies tailored to fa\u0026ccedil;ade orientation in cooling-dominated climates.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003e \u003cem\u003e5.4\u003c/em\u003e \u003cb\u003eDesign Implications\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eFor educational and institutional buildings in hot-dry climates, FRP louvers at a 45\u0026deg; rotation represent an optimal balance of solar protection and material durability.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eAluminum louvers can be preferable when daylighting remains a priority despite higher solar gains.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eTimber/WPC offers a mid-range option with good shading and sustainability tradeoffs, though considerations for maintenance and long-term performance in harsh environments are required.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec21\" class=\"Section2\"\u003e \u003ch2\u003e5.5 \u003cb\u003eContribution to Literature\u003c/b\u003e\u003c/h2\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eThis study advances fa\u0026ccedil;ade research by incorporating a detailed, comparative assessment of material-specific irradiance effects and spatial uniformity (standard deviation). It highlights thermal stability as a key performance metric alongside geometric and operational variables. The findings provide evidence-based guidance for selecting louver materials and configuring rotation angles to optimize solar control in hot-dry Indian climates.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"6. Conclusions","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eThis study evaluated the thermal performance of rotating louver fa\u0026ccedil;ades in a hot-dry climate through simulation-based analysis of three materials like aluminum, timber/WPC, and FRP, across rotation angles of 0\u0026deg;, 45\u0026deg;, and 90\u0026deg; on west and southwest orientations. The findings offer evidence-based insights for sustainable fa\u0026ccedil;ade design in Indian contexts:\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003ePerformance Effectiveness\u003c/b\u003e: Rotating louvers achieved a substantial 75\u0026ndash;80% reduction in annual solar irradiance compared to unshaded baselines, demonstrating their efficacy as a primary passive cooling strategy for buildings in hot dry climates.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eMaterial-Specific Insights\u003c/b\u003e: FRP louvers consistently outperformed other materials, delivering the lowest average irradiance (8.60-12.46 kWh/m\u0026sup2;/yr) and minimal spatial variation, indicating superior thermal stability. Timber/WPC proved effective in peak load reduction but exhibited moderate variability, while aluminum maintained higher minimum irradiance levels, potentially supporting daylighting needs at the expense of thermal performance.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eOrientation and Angle Optimization\u003c/b\u003e: Southwest fa\u0026ccedil;ades benefit most from shallow to mid-range angles (0\u0026deg;-45\u0026deg;) to address cumulative solar exposure, whereas west fa\u0026ccedil;ades require steeper configurations (45\u0026deg;-90\u0026deg;) to mitigate intense afternoon solar loads. The 45\u0026deg; rotation angle emerges as the optimal compromise, balancing average reduction, peak control, and uniform distribution across both orientations.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eDesign Recommendations\u003c/b\u003e: For educational and institutional buildings in hot dry India, FRP louvers at 45\u0026deg; rotation provide the most effective solar control with consistent thermal performance, making them suitable for large-scale implementation in climate-responsive architecture.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cdiv id=\"Sec23\" class=\"Section2\"\u003e \u003ch2\u003e6.1 Future Scope\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eTo build upon this work, the following research directions are recommended:\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eClimate Zone Extension\u003c/b\u003e: Expanding the analysis to other Indian climate zones composite, warm-humid, and temperate will validate the broader applicability of these findings and enable region-specific design guidelines.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eIntegrated Performance Metrics\u003c/b\u003e: Future research should incorporate daylight autonomy, glare indices, and occupant thermal comfort metrics to provide holistic fa\u0026ccedil;ade performance evaluation beyond solar heat gain reduction.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eReal-World Validation\u003c/b\u003e: Developing physical prototypes and field testing will validate simulation predictions and inform practical implementation strategies, including material durability and maintenance considerations.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eAutomated Control Systems\u003c/b\u003e: Investigating sensor-based, real-time louver control algorithms that respond to solar conditions, indoor temperature, and occupancy patterns will advance adaptive fa\u0026ccedil;ade technologies for Indian buildings.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eEconomic Feasibility\u003c/b\u003e: Conducting lifecycle cost analysis comparing initial investment, energy savings, and maintenance costs will support widespread adoption by architects and developers in the Indian construction industry.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e "},{"header":"Declarations","content":" \u003cp\u003eEthics, Consent to Participate, and Consent to Publish declarations: not applicable.\u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eNo funding was obtained.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eMaterial preparation, data collection and analysis were performed by Aditya Ghadgine and Ar. Ipsitaa Priyadarsini Das has worked on developing the methodology and reviewing the paper. All authors read and approved of the final manuscript.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eAll data generated or analysed during this study are included in this published article.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eIndia. electricity consumed share by sector 2024| Statista. Accessed: Sep. 24, 2025. [Online]. 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IS 875 (Part 3): 2015 \u0026ndash; Code of practice for design loads (other than earthquake) for buildings and structures: Part 3 \u0026ndash; Wind loads (Second Revision). New Delhi: Bureau of Indian Standards.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Rotating louvers, Solar control, Annual irradiance, Hot-dry climate, India, Kinetic facade","lastPublishedDoi":"10.21203/rs.3.rs-8827751/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8827751/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIndia\u0026rsquo;s building sector faces a rapidly increasing cooling demand, with fa\u0026ccedil;ades playing a decisive role in regulating solar heat gain. Static shading devices often fail to address dynamic solar exposure, particularly in hot-dry climates where west and south-west orientations receive intense cumulative radiation. Rotating louver fa\u0026ccedil;ades, as a form of adaptive envelope technology, offer the potential to reduce cooling loads while maintaining visual comfort. This study evaluates the thermal performance of rotating louvers constructed from aluminum, timber/wood-plastic composite (WPC), and fiber-reinforced polymer (FRP) in the hot-dry context of India. A representative classroom volume (7 \u0026times; 8 \u0026times; 3 m, WWR 40%) was modeled and simulated using parametric environmental analysis tools like Rhino/Grasshopper with Ladybug and Honeybee plugins and EnergyPlus. Louvers were tested at 0\u0026deg;, 45\u0026deg;, and 90\u0026deg; across west and south-west orientations. Results indicate that rotating louvers reduce annual solar irradiance by 75\u0026ndash;80% relative to unshaded baselines. Among materials, FRP consistently achieved the lowest average irradiance and variability, demonstrating superior thermal stability, while Timber/WPC reduced peak irradiance effectively and aluminum maintained higher minimum values, potentially aiding daylight penetration. Orientation and angle analysis revealed that SW fa\u0026ccedil;ades perform best with shallow mid rotations (0\u0026ndash;45\u0026deg;), while W fa\u0026ccedil;ades require mid steep angles (45\u0026ndash;90\u0026deg;) to control afternoon peaks. The findings provide evidence-based guidance for material and angle selection in adaptive fa\u0026ccedil;ades, offering practitioners actionable strategies to enhance energy efficiency and occupant comfort in hot-dry Indian climates.\u003c/p\u003e","manuscriptTitle":"Adaptive Solar Control Through Rotating Louvers: A Material- Based Performance Study in Hot-Dry India","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-06 22:04:41","doi":"10.21203/rs.3.rs-8827751/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"47da4f45-4c13-492f-9a91-e560b0d60ecf","owner":[],"postedDate":"March 6th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Rejected","date":"2026-04-30T04:46:52+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-30T04:54:43+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-06 22:04:41","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8827751","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8827751","identity":"rs-8827751","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}