Global warming increases the indoor temperature and energy consumption of residential buildings in arid regions. No doubt, development of effective passive cooling techniques are crucial to reduce the room air temperature as well as the energy consumption of buildings. The present study analyzes merits of a polystyrene foam - aluminium radiation reflector double skin system to be used as a passive cool roof in an arid region like Oman and assess the effect of air ventilation as a thermal barrier between the double skin layers. The present study incorporates a radiation reflective layer, dynamic air ventilation, and thermal insulation configurations. The study was performed in 3 stages for 0, 20 and 40 cm air ventilation between polystyrene-aluminium radiation reflector layers. It was confirmed by field experiments that a significant decrease in indoor and roof slab temperatures were observed for polystyrene-aluminium radiation reflector passive cool room in comparison to a traditional bare roof. The experimental studies reveal that comparing with a traditional roof, the room air temperature of double skin polystyrene-aluminium radiation reflector was reduced by 2.42 °C (6.7%), 3.69 °C (10.4%) and 4.7 °C (12.8%) for 0, 0.2 m and 0.4 m air ventilation between the polystyrene foam and aluminium reflector, respectively. The corresponding reduction in roof surface temperature was 6.91 °C (16.8%), 8.1 °C (24.5%) and 11.11 °C (31.9%) respectively. It was observed that the indoor air and roof surface temperature of the passive cool roof reduced as the air ventilation increased from 0 to 0.4 m. This proves that dynamic nature of air ventilation has a major role in improving the natural convective heat flux and thereby increase in thermal resistance of double skin roof. Also, Aluminium radiation reflector of the double-skin roof has high solar reflectance (albedo) which results in reduced short wave and long wave radiative heat flux to the ceiling in comparison with the conventional roof. Integration of polystyrene foam thermal insulator, air ventilation and aluminium radiation reflector in the passive cool roof system reduces conduction, convection, and radiation heat transfers, respectively between the roof and ceiling. It is conclusively proven that the double-skin polystyrene-aluminum radiation reflector passive cool roof with air ventilation can appreciably lower the room air and roof slab temperatures during hot sunny days.

全球变暖增加了干旱地区住宅建筑的室内温度和能耗。毫无疑问，开发有效的被动冷却技术对于降低室内空气温度和建筑物的能源消耗至关重要。本研究分析了聚苯乙烯泡沫 - 铝辐射反射器双层系统在阿曼等干旱地区用作被动冷却屋顶的优点，并评估空气通风作为双层表层之间的热屏障的效果。本研究结合了辐射反射层、动态空气通风和隔热配置。该研究分 3 个阶段进行，用于聚苯乙烯-铝辐射反射层之间的 0、20 和 40 厘米空气通风。现场实验证实，与传统的裸屋顶相比，聚苯乙烯-铝辐射反射器被动冷库的室内和屋顶板温度显着降低。实验研究表明，与传统屋顶相比，双层聚苯铝辐射反射器的室温降低了2.42°C（6.7%）、3.69°C（10.4%）和4.7°C（12.8%）聚苯乙烯泡沫和铝反射器之间分别有 0、0.2 m 和 0.4 m 的空气通风。屋顶表面温度的相应降低分别为 6.91 °C (16.8%)、8.1 °C (24.5%) 和 11.11 °C (31.9%)。观察到，随着通风量从 0 增加到 0.4 m，被动冷屋顶的室内空气和屋顶表面温度降低。这证明空气通风的动态特性在改善自然对流热通量从而增加双层屋顶的热阻方面具有重要作用。此外，双层屋顶的铝质辐射反射器具有较高的太阳反射率（反照率），与传统屋顶相比，可减少到天花板的短波和长波辐射热通量。在被动冷却屋顶系统中集成聚苯乙烯泡沫隔热材料、通风和铝辐射反射器，分别减少了屋顶和天花板之间的传导、对流和辐射热传递。最终证明，带通风的双层聚苯乙烯铝辐射反射器被动冷屋顶可以在炎热的晴天明显降低室内空气和屋顶板温度。