Tools and Rules-of-Thumb for Passive Design Strategies for Indian Climatic Conditions
Sakshi Nagpal, Prasad Vaidya | 2017
Energy required by the building sector in India accounts for 33% of the national energy use. Climate- responsive design can drive the building sector in India towards a low energy future because including passive design approaches and materials can decrease cooling by 60%–90% for new buildings and 50%– 90% for retrofits. Different passive design strategies are applicable for the 5 climate zones in India.
This study uses literature to identify prescriptive approaches to passive design strategies along with published rules of thumb. Of the 45 strategies identified through the literature research, only 19 were found to have rules-of-thumb that help sizing of building elements during design. For the 45 strategies, a Strategy Index for India is compiled, which includes the rules-of-thumb where available, applicable climatic as well as building conditions. Where specific values for climate conditions relevant to the strategies are not found and only generic climatic conditions, such as Hot-Dry, Warm-Humid or cold are found, the specific climatic conditions are derived by cross referencing the climate zone definitions and their threshold values from the literature. However, when this approach is applied to TMY weather data of Indian cities, it leads to recommendations that do not correspond with the strategies found in those cities. This analysis is presented in the paper. A monthly climate assessment method is proposed, which enables building designers to select passive design strategies that respond to seasonal variations within a climate. A Strategy Decision tool is formulated to help building designers select strategies that are applicable based on the local weather data and site conditions. Taken together, the Strategy Decision tool and the Strategy Index can be an important toolkit for building designers in India.