Energy retrofit analysis for an educational building in Mumbai
Vallary Gupta, Chirag Deb
Abstract
Buildings consume around 40% of total global primary energy and account for one-third of greenhouses gas emissions. In the context of rising average air temperature and growing reliance on air-conditioning for space cooling, energy efficiency in buildings is becoming increasingly important. This is of particular significance to the tropics where a high rate of construction and development is expected in the coming decades. The present study evaluates the impact of several envelope retrofit materials on indoor air temperatures and energy consumption for space cooling for an educational building at IIT Bombay in Mumbai, India. The parametric study is performed using Rhino/ Grasshopper plugins LadyBug and HonyeBee and validated using measured indoor air temperature data. The energy performance is evaluated by applying thermal insulation with and without reflective coating, green roof and bamboo-based shading systems in the simulation environment. From all the retrofit alternatives, it is found that increasing the envelope's insulation followed by the provision of natural shading system results in largest reductions in cooling loads. The combined system has shown to produce maximum energy savings of up to 25% and reduce number of hours with indoor air temperatures higher than 35°C by up to 60% for an annual time period. The results offer ways to mitigate energy consumption and carbon footprint of similar buildings in the tropics.