An assessment of the impact of passive design variations of the building envelope using thermal discomfort index and energy savings in warm and humid climate

Over the years, the commercial buildings sector has emerged as one of India’s fastest-growing sector and the commercial space is expected to grow four fold between 2015 and 2030. Due to the absence of thermal comfort regulations in India, designers frequently overdesign cooling systems in accordance with international norms, leading to unsustainable practises and energy wastage. The conventional building construction in India’s warm and humid climate make people uncomfortable due to heat gains, forcing the use of cooling equipment that require a lot of energy. Use of passive design options in the building envelope is thought to be a viable strategy for lowering energy usage. The different effects of building exterior components and passive design solutions on the indoor thermal environment can be effectively integrated using the criterion of thermal comfort. A new thermal discomfort index based on adaptive comfort using the numerical method and trapezoidal rule is established and used as a basis of comparison to assess the relative performance of building envelopes. In comparison to the reference building envelope in warm, humid climate, the research shows that careful attention to building envelope design with consideration of various passive options can improve the indoor thermal environment by 5.82 °C, reduce thermal discomfort by 80.75 percent and save energy up to 77 percent