Structural Configuration and Thermal Behaviour of Buildings

Abstract

Energy consumption due to space cooling and lighting has been found to account for one third of total energy consumption in residential buildings and two-thirds of total energy consumption in commercial buildings in India (Bhatt, Rajkumar, Jothibasu, Sudirkumar, Pandian, and Nair, 2005). The use of air conditioners in multi-storeyed residential buildings has been found to increase the Energy Performance Index (EPI) by nearly twice. AC use has been attributed to poor performance of building envelope (comprising of roofs, external walls and fenestrations) in meeting with the thermal comfort requirements of occupants (Rawal and Shukla, 2014). Commercial buildings are typically used during the day-time when cooling loads are the highest. It is estimated that by 2030, 60% of the commercial space in India will be air-conditioned. (cbalance and Fairconditioning program). newlineThe aim of the research is to study the structural configuration of buildings and their influence on its thermal behavior with an objective of providing guidelines for energy efficient, even net zero energy buildings, thus reducing building s reliance on fossil fuels. newlineStudies of structural configuration included Relative Compactness, Wall Window Ratio and Skylight to Roof Ratio, Solar Heat Gain Coefficient, Thermal transmittance (U value) of wall, roof and fenestrations and effect of passive design strategies such as orientation, radiant barrier, Direct Structural Cooling (DSC), spatial layout and natural ventilation. Thermal behavior was studied using measured environmental variables ie. Dry bulb temperature (DBT), Relative Humidity (RH), Surface Temperature, Globe temperature (Mean Radiant Temperature - MRT) and Air Speed. Calculated derivatives included Operative Temperature (OT), Envelope Performance Factor (EPF) and Envelope Thermal Transfer Value (ETTV), Thermal Comfort Indices such as the Tropical Summer Index (TSI). Outcome-based benchmarks such as the Energy Performance Index (EPI) were also used. newlineOn-site measurements of DBT, RH, Surface tempera