en عمومى General مقاله اصیل Original Article <div style="text-align: justify;">Introduction: In hot-arid climates, optimizing window design is crucial for balancing energy and visual comfort, which can affect environmental health and efficiency in educational buildings.<br> Methods: A single south-facing classroom (8 m &times; 6 m &times; 3 m) in Kerman was simulated using DesignBuilder software. Variables included Window-to-Wall Ratio (WWR: 10%&ndash;60%), number of windows (1&ndash;5), and orientation (horizontal vs. vertical). Energy consumption (site, source, heating, cooling loads) and Daylight Factor (DF) were evaluated for 60 models.<br> Results: No model with 10% WWR achieved the minimum required DF ( &ge; 2%). With 20% WWR, only 1&ndash;2 vertical windows met DF &ge; 2%, with 1 vertical window being optimal (the lowest source energy: 376.82 kW.h). With 30% WWR, 5 vertical windows were optimal (source energy: 383.86 kW.h, DF: 2.609%). With 40% WWR, 5 vertical windows performed best (source energy: 402.33 kW.h, DF: 3.965%). With 50% WWR, 4 horizontal windows were optimal (source energy: 414.41 kW.h, DF: 2.146%). With 60% WWR, 5 horizontal windows were optimal (source energy: 429.48 kW.h, DF: 2.566%). Cooling load had a greater influence on total energy consumption than heating load.<br> Conclusion: In hot-arid climates like Kerman, vertical windows are more efficient at lower WWRs (20%&ndash;40%), while horizontal windows perform better at higher WWRs (50%&ndash;60%). The overall optimal configuration was 20% WWR with one vertical window, providing minimal energy consumption, which creates environmental health in terms of daylight comfort.</div> Daylighting, Energy efficiency, Window design, Classroom, Design builder 1 9 http://ehemj.com/browse.php?a_code=A-10-1-451&slc_lang=en&sid=1 Neda Daei Parizi Neda.da.pa@gmail.com 100319475328460022201 0009-0000-8228-9052 No Department of Architecture, Bam.C., Islamic Azad University, Bam, Iran Mansour Nikpour Mansour.Nikpour@iau.ac.ir 100319475328460022202 100319475328460022202 Yes Correspondence to: Department of Architecture, Bam.C., Islamic Azad University, Bam, Iran Hossein Fallah hossein.fallah@iau.ac.ir 100319475328460022203 100319475328460022203 No Department of Architecture, Bar.C., Islamic Azad University, Bardsir, Iran