Comparative Assessment of Climate‐Responsive Insulation Strategies for Energy Efficiency, Moisture Control, and Thermal Comfort in Humid and Hot‐Dry Iranian Climates

Buildings account for over 35% of Iran′s energy use, yet insulation performance is climate dependent and may involve trade‐offs between energy demand, indoor humidity exposure, and thermal comfort. This study quantifies how climate‐adapted thermal and moisture insulation strategies perform differently under two contrasting Iranian cities (humid Rasht vs. hot‐dry Yazd). We test the hypothesis that climate‐tailored envelope packages outperform a uniform approach when evaluated jointly for energy, indoor humidity screening metrics, and PMV/PPD comfort outcomes, while acknowledging climate‐specific trade‐offs. Using EnergyPlus with 20‐year city‐specific weather data, we simulated a prototypical detached residence and compared climate‐adapted wall assemblies (Rasht: mineral wool with an interior vapor‐control layer; Yazd: continuous XPS) and two glazing options (conventional vs. Low‐E, via Simple Glazing System). Model predictions were validated against field data (monthly energy within 10%). Results show that Rasht is heating dominated, whereas Yazd is cooling dominated in summer. In Rasht, the optimized wall reduced indoor RH exceedance above 70% from 312 to 0 h/year (screening indicator of high‐humidity exposure) and shifted winter PMV from ~−1 to near neutral. In Yazd, Low‐E glazing reduced cooling energy by ~12% and improved summer comfort from PMV > +1 to near neutral (PPD < 10%). Overall, the comparative results indicate that climate‐adapted insulation strategies can improve performance, but the dominant mechanisms and optimal measures differ by climate, supporting climate‐indexed envelope guidance for Iranian practice.