An Analytical Assessment and Retrofit Using Nanomaterials of Rural Houses in Heat Wave-Prone Region in India

Abstract

The Indian state of Andhra Pradesh experiences intense heat wave in the summer months. It is important to assess the indoor comfort hours of rural houses which are built with locally available materials because of economic constraints. This study aims to gauge the embodied energy and heat conductance of the houses in the heat wave-prone hot and humid climate of Vijayawada, Andhra Pradesh, and suggest retrofit to better the indoor thermal environment. A field study of four houses with different walling materials and the same roofing material of a typical village is carried out, and their embodied energy and thermal performance are compared with a conventional modern house from the same location. HTC-AMV06 Thermometer is used for field measurements of indoor dry bulb temperature and humidity, and the globe thermometer is used for outdoor temperature data on a summer day in April. Thermal energy models are simulated in energy plus and correlated with recorded data to validate the models. Validated models are used for computing indoor comfort hours. Embodied energy analysis shows that a house made with a reed wall and mud plaster with a reed roof has the lowest embodied energy (473.5 MJ/m2). It is only 9.47% of the conventional house which has very high embodied energy (5002.2 MJ/m2). Comfort hours for all the houses lie in a narrow range of 51.4–47.18% irrespective of the variation in embodied energy. Aerogel, when used as an insulation material, reduces indoor temperature by 11.09 °C in cement block houses and 6.17 °C in random rubble houses.