Parametric Study of the Impact of Windows to Wall Ratio on Reduction of Energy Consumption and Environmental Impact of a Zero-Energy Building in Different Orientations

Document Type: Research Paper


Department of Mechanical Engineering, University of Sistan and Baluchestan, Zahedan, Iran


Nowadays, the increase of fossil fuel consumption intensifies the crucial role of architects. As buildings consume over one-third of the used energy, the society of architects is held responsible for this consumption. Therefore, the amount of energy used by a building is directly related to its design; meaning that reduction of energy consumption should be targeted at the design stage. In this research, the proper building form with the lowest energy consumption for heating, cooling, and lighting was obtained after studying different shapes in Design Builder Software, and it was concluded that the building form has a significant impact on energy consumption. After the parametric studies, the best building orientation of 60 degrees north-east and a window-wall ratio (WWR) of 40% was obtained. Moreover, the building considered for this study had annual CO2 emissions of 30 tons, which was reduced to around 15 tons of CO2 emissions in a year at the optimum degree and WWR, i.e. a reduction of CO2 emissions to half of its previous amount.


Main Subjects

[1]          H. J. Kwon, S. H. Yeon, K. H. Lee, and K. H. Lee, “Evaluation of Building Energy Saving Through the Development of Venetian Blinds ’ Optimal Control Algorithm According to the Orientation and Window-to-Wall Ratio,” Int. J. Thermophys., 2018.

[2]          K. Petrichenko, D. Ürge-vorsatz, and L. F. Cabeza, “Energy & Buildings Modeling global and regional potentials for building-integrated solar energy generation,” vol. 198, pp. 329–339, 2019.

[3]          G. Feng, D. Chi, X. Xu, B. Dou, Y. Sun, and Y. Fu, “ScienceDirect ScienceDirect Study on the Influence of Window-wall Ratio on the Energy Consumption of Nearly Zero Energy Buildings,” Procedia Eng., vol. 205, pp. 730–737, 2017.

[4]          G. Syngros, C. A. Balaras, and D. G. Koubogiannis, “Embodied CO 2 Emissions in Building Construction Materials of Hellenic Dwellings,” Procedia Environ. Sci., vol. 38, pp. 500–508, 2017.

[5]          M. Mahdavi Adeli, S. Farahat, and F. Sarhaddi, “Analysis and Optimization using Renewable Energies to Get Net-Zero Energy Building for Warm Climate,” J. Comput. Appl. Mech., vol. 48, no. 2, pp. 331–344, 2017.

[6]          X. Su and X. Zhang, “Environmental performance optimization of window – wall ratio for different window type in hot summer and cold winter zone in China based on life cycle assessment,” Energy Build., vol. 42, pp. 198–202, 2010.

[7]          R. Azari, S. Garshasbi, P. Amini, H. Rashed-ali, and Y. Mohammadi, “Multi-Objective Optimization of Building Envelope Design for Life Cycle Environmental Performance,” Energy Build., 2016.

[8]          G. Lobaccaro, A. H. Wiberg, G. Ceci, M. Manni, N. Lolli, and U. Berardi, “PT,” Energy Build., 2018.

[9]          F. Goia, “Search for the optimal window-to-wall ratio in office buildings in different European climates and the implications on total energy saving potential,” Sol. Energy, vol. 132, pp. 467–492, Jul. 2016.

[10]        A. Charles, W. Maref, and C. M. Ouellet-plamondon, “Case study of the upgrade of an existing office building for low energy consumption and low carbon emissions,” Energy Build., 2018.

[11]        R. Moschetti, H. Brattebø, and M. Sparrevik, “Exploring the pathway from zero-energy to zero-emission building solutions: A case study of a Norwegian office building,” Energy Build., 2019.

[12]        S. Pathirana, A. Rodrigo, and R. Halwatura, “Effect of building shape , orientation , window to wall ratios and zones on energy efficiency and thermal comfort of naturally ventilated houses in tropical climate,” Int. J. Energy Environ. Eng., no. 0123456789, 2019.

[13]        N. Harmati and Z. Magyar, “Influence of WWR , WG and glazing properties on the annual heating and cooling energy demand in buildings,” Energy Procedia, vol. 78, pp. 2458–2463, 2015.

[14]        M. Alwetaishi, “Journal of King Saud University – Engineering Sciences Impact of glazing to wall ratio in various climatic regions : A case study,” J. King Saud Univ. - Eng. Sci., pp. 1–13, 2017.

[15]        Z. S. Zomorodian and M. Tahsildoost, “Energy and carbon analysis of double skin façades in the hot and dry climate,” J. Clean. Prod., vol. 197, pp. 85–96, 2018.

[16]        J. Khalesi and N. Goudarzi, “Thermal comfort investigation of stratified indoor environment in displacement ventilation: Climate-adaptive building with smart windows,” Sustain. Cities Soc., vol. 46, p. 101354, Apr. 2019.

[17]        M. Valizadeh, F. Sarhaddi, and M. Mahdavi Adeli, “Exergy performance assessment of a linear parabolic trough photovoltaic thermal collector,” Renew. Energy, vol. 138, pp. 1028–1041, Aug. 2019.

[18]        J. Yazdanpanahi, F. Sarhaddi, and M. Mahdavi Adeli, “Experimental investigation of exergy efficiency of a solar photovoltaic thermal (PVT) water collector based on exergy losses,” Sol. Energy, vol. 118, pp. 197–208, Aug. 2015.

[19]        M. Mahdavi Adeli, F. Sobhnamayan, S. Farahat, M. Abolhasan Alavi, and F. Sarhaddi, “Experimental Performance Evaluation of a Photovoltaic Thermal,” Strojniški Vestn. - J. Mech. Eng., vol. 58, no. 5, pp. 309–318, 2012.

[20]        A. Namjoo, F. Sarhaddi, F. Sobhnamayan, M. A. Alavi, M. Mahdavi Adeli, and S. Farahat, “Exergy performance analysis of solar photovoltaic thermal (PV/T) air collectors in terms of exergy losses,” J. Energy Inst., vol. 84, no. 3, 2011.

[21]        M. Mahdavi Adeli, F. Sobhnamayan, M. Abolhasan Alavi, S. Farahat, and F. Sarhaddi, “Experimental exergetic performance evaluation of a photovoltaic thermal (PV/T) air collector and comparison with numerical simulation,” Proc. Inst. Mech. Eng. Part E J. Process Mech. Eng., vol. 225, no. 3, pp. 161–172, 2011.

[22]        F. Sarhaddi, S. Farahat, H. Ajam, A. Behzadmehr, and M. Mahdavi Adeli, “An improved thermal and electrical model for a solar photovoltaic thermal (PV/T) air collector,” Appl. Energy, vol. 87, no. 7, pp. 2328–2339, Jul. 2010.

[23]        EnergyPlus, “The board of US Department of Energy (DOE). October 1, (2013). ,” EnergyPlus Eng. Ref., 2016.

[24]        N. M. Patil and M. B. Kumthekar, “Low Carbon Building,” Int. Res. J. Eng. Technol., vol. 3, no. 12, 2016.