Environmental Optimization of Building Insulation Thickness in Warm-Dry Regions

Document Type: Original Article


Department of Mechanical Engineering, Faculty of Engineering, Kharazmi University, Tehran, Iran


In this study, the environmental effect ( ) of rock wool as a mineral insulation material and expanded polystyrene as a polymer insulation material for a residential building is studied. Initially, the intended building is simulated in Design Builder for warm-dry climate regions like Yazd and Isfahan cities and then the effect of different thicknesses of these two insulation materials inside the external wall of the building is studied towards optimizing the thickness value environmentally. Despite the  emissions generated by cooling and heating systems while consuming energy throughout the year, embodied  values in the manufacturing process until installation are also considered. Eventually, using the Energy Plus simulation engine inside Design Builder and MATLAB software, the environmental optimum insulation thickness regarding emission and embodied values of  for a lifetime of ten years in warm-dry regions of Iran such as Yazd and Isfahan cities are calculated. These values for expanded polystyrene are found to be 20 cm for Isfahan and 19 cm for Yazd and values for rock wool are 11 cm for Isfahan and 10 cm for Yazd. Thus, a mineral insulation material such as rock wool has a smaller environmental optimum insulation thickness than a polymer insulation material such as expanded polystyrene.


[1] M. Dixit, J. Fernández, S. Lavy and C. Culp, Energy Build., 42, (2010), 1238.

[2] Ö. A. Dombayci, Ö. Atalay, Ş. G. Acar, E. Y. Ulu, and H. K. Ozturk, Sustain Energy Techin., 22, (2017), 1.

[3] Q. Jin, F. Favoino and M. Overend, Energy, 127,(2017), 634.

[4] Saafi, Khawla, and Naouel Daouas. "A life-cycle cost analysis for an optimum combination of cool coating and thermal insulation of residential building roofs in Tunisia." Energy, 152 (2018).

[5] D. Hittle The building loads analysis and system thermodynamics (BLAST) program, CERL, Technical Report, US Army construction engineering research laboratory, Champaigon, Illinois, (1977) E-119.

[6] K. BLAST, Building loads analysis system thermodynamics, User’s manual, Version 3, University of Illinois, Urbana, Champain, Blast support office, Il., USA, (1986).

[7] L DOE. Engineers manual, version 2.1A, LBL 11353, Lawrence Berkeley laboratory, the national technical information service (NTIS) provides DOE-2 documentation De-830-04575, Berkley CA, (1982).

[8] G. Hudson, Underwood C P. "A Simple building modelling procedure for MATLAB/Simulink", Proceedings of the 6th International Conference on Building Performance Simulation (IBPSA99), Kyotojapan, (1999), 2, 777.

[9] T. Kusuda, Hill J E, Liu S T, Barnett J P, Bean J W. Pre-design analysis of energy conservation options for a multi-story demonstration office building, Final Report National Bureau of standards, Washington DC,(1975).

[10] A. Al-Turki, and G. M. Zaki, Energy Convers. Manage., 32.3 (1991), 235.

[11] J. S. Lim and A. Bejan, Heat Trans Eng., (1994), 15, 35.

 [12] N. Mendes and G. Santos, Dynamic analysis of building hydrothermal behavior, proceeding of the 7th Int IBPSA Conference Building Simulation, Rio de janiro, Brazil., (2001), 1, 117.

[13] M. F. Alsayed and R. A. Tayeh, J. Build. Eng. (2018), 22, 101.

[14] L. Sagbansua and F. Balo, Energy Build., (2017), 148, 1.

[15] N. A. Kurekci, Energy Build., (2016), 118, 197.

[16] M. Ozel, Appl. Therm. Eng., (2019), 147, 770.

[17] N. Daouas, Z. Hassen and H. Ben, Appl. Therm. Eng. (2010), 30, 319.

[18] G. Özel, E. Açikkalp, B. Görgün, H. Yamik and N. Caner, Energy Technol. Assess., (2015), 11, 87.

[19] D. B. Özkan and C. Onan, Appl. Energy, (2011), 88, 1331.

[20] E. A. Rad and E. Fallahi, Constr Build Mater., (2019), 205, 196.