Influence of balcony greenery on indoor temperature reduction in tropical urban residential buildings

Urbanization poses significant challenges, including strain on infrastructure, environmental degradation from increased resource consumption and pollution, and climatic impacts like the urban heat island phenomenon, which contributes to elevated city temperatures. Urban greenery effectively reduces urban heat stress; however, space constraints often limit implementation. This study uses experimental measurements and simulation analysis to examine the impact of residential greenery on indoor temperature regulation in a three-storey apartment in a tropical region. Experimental data were collected from a north-facing balcony with plants, measuring air temperature and humidity during the peak dry season. The residential greenery showed lower temperatures than the reference one. The most significant indoor temperature difference was 2.5 °C with a combination of potted plants and a living wall, followed by 1.0 °C for the living wall and 0.8 °C for the potted plants alone. A simulation study on seasonal and orientation indicated that the living wall was most effective for cooling in the west and east during the dry season, reducing surface temperatures by up to 4.5 °C and 4.3 °C, respectively. They helped regulate wet season temperatures in the north, reducing them by 2.6 °C. One-sided balcony enclosures with 75 % living wall coverage were most efficient in enhancing natural ventilation and cooling on lower floors, while upper floors experienced higher temperatures. The findings highlight the impact of residential greenery on thermal comfort by reducing indoor temperatures, demonstrating its potential as a viable solution for enhancing urban green spaces amid urbanization challenges.