Analysis of Indoor Thermal Environment Improvement in Apartment Buildings through the Application of Heat-Reflective Paint

Urban heat islands and rising global temperatures are increasing the need for passive cooling solutions in densely populated areas. This study examines the effectiveness of heat-reflective paint in reducing surface and indoor temperatures in a 33-year-old apartment complex in Gumi City, South Korea. Using mock structures to simulate real building conditions, the experiment measured surface and indoor temperatures in both treated and untreated groups. Data collected from thermal imaging cameras and data loggers demonstrated significant temperature reductions on the treated walls, with surface temperatures lowering by 2.2°C to 4.3°C on average, and peak reductions of up to 15.3°C. Internally, the treated structures showed temperature reductions between 2.1°C and 4.1°C, with the largest difference observed during peak heat hours at 4.14°C. The results highlight the effectiveness of heat-reflective paint in mitigating heat stress and improving indoor thermal comfort, particularly in regions with high solar exposure. Importantly, this study aims to benefit vulnerable populations, such as the elderly and economically disadvantaged residents, by providing a cost-effective, sustainable solution to reduce heat exposure in aging urban buildings, thereby enhancing their quality of life.