Thermal Insulation Performance of Radiant Barrier Roofs for Rural Buildings in the Qinba Mountains

Strengthening the roof insulation is the main method for improving the indoor thermal environment of rural buildings during summer. This study proposed a radiant barrier roof with a roof insulation structure based on climatic conditions in the Qinba Mountains and the characteristics of rural buildings, in which radiant barriers were installed on the underside of the roof in the attic space to enhance roof insulation. To study the thermal insulation performance of radiant barrier roofs, aluminum foil bubble composites were installed on the underside of the roof in the attic space in the Qinba Mountains, and comparative experiments were carried out. Based on the results, the average temperature of the second-floor bedrooms dropped by 1.1°C, thus proving the effectiveness of thermal insulation with radiant barrier roofs. The thermal insulation performance of radiant barrier roofs made of aluminum foil bubble composite was studied through numerical simulation analysis. Based on the findings of this study, radiant heat transfer contributed 65% to the thermal insulation effect when aluminum foil bubble composites were applied. Based on the analysis of thermal performance and cost, it is recommended to use radiant barrier materials with an emissivity of less than 0.3 and a thermal resistance of no more than 2 m2K/W. Furthermore, the application of radiant barrier roofs made of aluminum foil bubble composites can have a positive effect on thermal insulation during winter. This facilitates the widespread use of radiant barrier roofs for rural buildings throughout hot-summer/cold-winter zones.