Scientific Journal Impact Factor (SJIF): 1.711 International Journal of Modern Trends in Engineering and Research www.ijmter.com     126 e-ISSN: 2349-9745 p-ISSN: 2393-8161 Modeling and performance evaluation of energy efficient buildings envelope using exergy analysis method Rishabh Agrawal 1 ,S.C.Kaushik 2 1,2 Centre for Energy Studies, Indian Institute of Technology, Delhi, Hauz Khas 110016, India Abstract-In the present study, the extended concept of exergy analysis has been applied to a building located in New Delhi with a volume of 60 m 3 and having a single-glazed window on the south facing wall .With this study thermal energy and thermal exergy flow were investigated to calculate the total thermal energy and exergy in and out from the building. This allows performing a complex exergy analysis of the building in both heating and cooling cases. The calculations were carried out by using the developed mathematical model of building and measured solar radiation data on horizontal and vertical wall surface. The thermal energy and thermal exergy flows for a space of a typical residential building of natural ventilation system with different parametric changes (i.e. wall thickness, roof thickness, window material properties, window dimensions, wall material thermal conductivity ) have been modelled and compared from the reference case . Keywords-Thermal energy and thermal exergy, building envelope, thermal conductivity, convective and radiative heat transfer co-efficient. I. Introduction In many countries, the energy required for building space conditioning has the highest share of total energy consumed in residential sector. The building sector represents about 33% of electricity consumption in India, with commercial sector and residential sector accounting for 8% and 25% respectively [1] and a major share of this energy is used to maintain thermal comfort inside the building at around 20 o C. All kinds of energy utilization calculations, including cooling/heating loads of rooms in buildings are based on energy conservation laws means based on the first law of thermodynamics. To carry out the detail analysis of the energy flow processes can be applied second law of thermodynamics, in which entropy concept described as well, in addition to first law of thermodynamics. Because of the low temperature range, the required exergy demand for heating and cooling application is low, which is generally met by high grade energy source (i.e. electricity).The widely held perception is that about 30% to 40% of annual global energy consumption is due to buildings and 60% of that is due to HVAC. In India, HVAC and lighting appliances were the main parts of the energy