Integrating Green Walls for Thermal Comfort and Energy Efficiency in Commercial Buildings

Thesis Abstract

The increasing energy consumption of commercial buildings and the growing demand for sustainable architectural solutions necessitate innovative strategies to enhance thermal comfort while reducing operational costs. Green walls, an increasingly popular biophilic design feature, have shown potential in moderating indoor environmental conditions; however, systematic evaluation of their effectiveness in commercial settings remains limited. This study aims to assess the integration of green walls in commercial buildings to improve thermal comfort and enhance energy efficiency, with specific objectives including quantifying the influence of green walls on indoor temperature regulation, evaluating their impact on energy consumption for HVAC systems, and identifying occupant perceptions concerning thermal comfort and aesthetic benefits. Employing a mixed-methods research design, the study combines quantitative data collection through instrumented monitoring and energy audits with qualitative insights from occupant surveys and interviews. A purposive sampling approach was used to select ten commercial buildings in metropolitan regions with similar climatic conditions, comprising five buildings equipped with green walls and five without. The sample size included 300 occupants (30 per building) for surveys, and detailed thermal and energy data were collected over a 12-month period using data loggers, smart meters, and building management systems. To analyze the quantitative data, multiple regression analysis was applied to determine the relationship between green wall features and indoor thermal stability, while ANOVA was used to compare energy consumption across the two groups. The qualitative data were analyzed through thematic analysis to extract recurring themes regarding occupant perceptions of thermal comfort and aesthetics. Preliminary findings are expected to demonstrate that buildings with integrated green walls exhibit more stable indoor temperatures, reducing temperature fluctuations by an average of 2.5°C, compared to conventional buildings. The energy audit results are anticipated to reveal a statistically significant reduction of approximately 18% in cooling energy consumption in green wall-equipped buildings. The regression models are expected to show that variables such as green wall thickness, plant species, and maintenance frequency significantly contribute to indoor thermal regulation. Additionally, occupant surveys are projected to indicate higher satisfaction with thermal comfort levels and aesthetic appeal in green wall buildings, corroborated by positive qualitative feedback emphasizing reduced noise and improved air quality. This research contributes to the body of knowledge by providing empirical evidence documenting the thermal and energy performance benefits of green walls in commercial contexts, thus bridging existing gaps in the literature predominantly focused on residential or experimental settings. The theoretical framework integrates the Biophilia Hypothesis, which posits human affinity for nature, and the Principles of Sustainable Building Design, grounding the environmental benefits of green walls within broader architectural and physiological theories. The study concludes that integrating green walls into commercial building design is a viable strategy for enhancing thermal comfort and reducing energy consumption, supporting broader sustainability initiatives. Recommendations include adopting standardized design guidelines for green wall implementation, developing maintenance protocols to maximize performance, and encouraging policy incentives to promote biophilic architecture. Future research should explore long-term durability, cost-effectiveness analyses, and the integration of green walls with other sustainable building systems to optimize environmental and economic benefits further.