Energy and Economic Analysis of Optimum Insulation Thickness for Exterior Walls in Sakarya Province

Meryem Coşkunsu; Murat Cuma; Emel Çelik; Yusuf Çay

doi:10.29130/dubited.1864176

TR EN

Abstract

Bu çalışmada, Sakarya ili iklim koşulları altında konut binalarının dış duvarlarına uygulanan ısı yalıtım kalınlığının enerji tüketimi ve ekonomik performans üzerindeki etkileri incelenmiştir. Analizler TS 825 standardına uygun olarak gerçekleştirilmiştir. Yıllık ısıtma enerjisi ihtiyacı, 2015–2024 dönemine ait on yıllık ortalama ısıtma derece-gün (HDD) değeri kullanılarak hesaplanmış ve böylece uzun dönemli iklim koşullarını temsil eden bir değerlendirme yapılmıştır. Farklı yalıtım kalınlıkları için dış duvarın toplam ısı geçiş katsayısı (U) ve buna karşılık gelen yıllık enerji ihtiyacı, derece-gün yöntemi kullanılarak belirlenmiştir. Ekonomik değerlendirmeler, başlangıç yalıtım yatırım maliyeti ile on yıllık dönem boyunca oluşan enerjiye bağlı işletme maliyetlerinin birlikte ele alındığı yaşam döngüsü maliyeti yaklaşımına dayalı olarak yapılmıştır. Ayrıca, yakıt birim fiyatındaki değişimlerin ekonomik optimum yalıtım kalınlığı üzerindeki etkisini değerlendirmek amacıyla bir duyarlılık analizi gerçekleştirilmiştir. Elde edilen sonuçlar, yalıtım kalınlığının artırılmasının yıllık enerji ihtiyacında önemli bir azalma sağladığını; ancak belirli bir kalınlığın ötesinde ilave enerji tasarrufunun sınırlı kaldığını göstermiştir. Toplam maliyet analizi, enerji maliyetleri ile yalıtım yatırım maliyetleri arasında ekonomik bir dengenin belirli bir kalınlık aralığında sağlandığını ve bu aralığın ekonomik optimum yalıtım kalınlığına karşılık geldiğini ortaya koymuştur. Duyarlılık analizi ise yakıt birim fiyatlarındaki artışların toplam yaşam döngüsü maliyetlerini yükselttiğini ve optimum yalıtım kalınlığını daha yüksek değerlere kaydırdığını göstermiştir. Bu bulgular, bina enerji verimliliği uygulamalarında yalıtım kalınlığının belirlenmesinde enerji ve ekonomik kriterlerin yanı sıra yakıt fiyatı senaryolarının da dikkate alınmasının önemini vurgulamaktadır.

Keywords

Optimum yalıtım kalınlığı;, Enerji verimliliği;, Yaşam döngüsü maliyeti;

Energy and Economic Analysis of Optimum Insulation Thickness for Exterior Walls in Sakarya Province

Abstract

In this study, the effects of thermal insulation thickness applied to the exterior walls of residential buildings on energy consumption and economic performance were investigated under the climatic conditions of Sakarya Province. The analyses were conducted in accordance with the TS 825 standard. Annual heating and cooling energy demands were calculated using average heating degree-day (HDD) and cooling degree-day (CDD) values for the 2015–2024 period to represent long-term climatic conditions. The overall heat transfer coefficient (U), annual energy demand, life cycle cost (LCC), optimum insulation thickness, and payback period were determined for different insulation materials and insulation thicknesses. The economic analysis incorporated insulation investment cost, energy cost, interest and inflation rates, and fuel price sensitivity over a ten-year analysis period. Increasing insulation thickness significantly reduced annual energy demand; however, the additional energy savings gradually diminished beyond the optimum thickness. Depending on the insulation material, the economically optimum insulation thickness ranged from 6 to 8 cm, while higher fuel prices shifted the optimum thickness toward greater values. The results provide practical guidance for determining economically optimum insulation thicknesses and improving energy-efficient building design in regions with climatic conditions similar to those of Sakarya Province.

Keywords

Optimum insulation thickness, Life cycle cost, Heating and cooling energy demand, Sensitivity analysis, Degree-day method

Supporting Institution

This research received no external funding.

Ethical Statement

This study does not involve human or animal participants. All procedures were conducted in accordance with scientific and ethical principles, and all referenced studies have been appropriately cited.

Thanks

This research did not receive any funding, but we would like to thank Aker Architecture-Engineering for their contribution to the realization of the study. We would also like to thank the relevant institutions for providing the IZODER Program used in the calculations for the TS-825 standard.

References

Ajabli, H., Zoubir, A., Elotmani, R., Louzazni, M., Kandoussi, K., & Daya, A. (2023). Review on eco-friendly insulation material used for indoor comfort in building. Renewable and Sustainable Energy Reviews, 185, Article 113609. https://doi.org/10.1016/j.rser.2023.113609
Akca, A. H. (2025). Effect of the degree of the color darkness of the building envelope on the annual energy requirement of the building calculated according to TS 825. Black Sea Journal of Engineering and Science, 8(5), 1349–1357. https://doi.org/10.34248/bsengineering.1707841
Aksa Natural Gas Distribution Inc. (2026). Subscriber and Free Consumer Sales Tariff. Retrieved January 15, 2026, from https://www.aksadogalgaz.com.tr/tr/musteri-hizmetleri/fiyat-tarifeleri/satis-tarifesi
Aktemur, C., Bilgin, F., & Tunçkol, S. (2021). Optimization on the thermal insulation layer thickness in buildings with environmental analysis: An updated comprehensive study for Turkey’s all provinces. Journal of Thermal Engineering, 7(5), 1239–1256. https://doi.org/10.18186/thermal.978057
Aktemur, C., Çakır, M. T., & Çakır, M. F. (2024). Optimizing thermal insulation thickness based on wall orientations and solar radiation using heating-degree hour method. Case Studies in Thermal Engineering, 60, Article 104725. https://doi.org/10.1016/j.csite.2024.104725.
Ang, J. H., Yusup, Y., Zaki, S. A., Salehabadi, A., & Ahmad, M. I. (2022). Comprehensive energy consumption of elevator systems based on hybrid approach of measurement and calculation in low- and high-rise buildings of tropical climate towards energy efficiency. Sustainability, 14(8), Article 4779. https://doi.org/10.3390/su14084779
Asghari, M., Fereidoni, S., Fereidooni, L., Nabisi, M., & Kasaeian, A. (2024). Energy efficiency analysis of applying phase change materials and thermal insulation layers in a building. Energy and Buildings, 312, Article 114211. https://doi.org/10.1016/j.enbuild.2024.114211
Aydın, N., & Bıyıkoğlu, A. (2019). Determination of optimum insulation thickness based on heating load by life-cycle cost analysis for residential buildings in Turkey. Journal of Polytechnic, 22(4), 901–911. https://doi.org/10.2339/politeknik.435773
Berardi, U., & Naldi, M. (2017). The impact of the temperature dependent thermal conductivity of insulating materials on the effective building envelope performance. Energy and Buildings, 144, 262–275. https://doi.org/10.1016/j.enbuild.2017.03.052
Bergman, T. L., Lavine, A. S., Incropera, F. P., & DeWitt, D. P. (2011). Fundamentals of heat and mass transfer (7th ed.). Wiley.

Bolattürk, A. (2008). Optimum insulation thicknesses for building walls with respect to cooling and heating degree-hours in the warmest zone of Turkey. Building and Environment, 43(6), 1055–1064. https://doi.org/10.1016/j.buildenv.2007.02.014
Cuce, E., Cuce, P. M., Wood, C. J., & Riffat, S. B. (2014). Toward aerogel based thermal superinsulation in buildings: A comprehensive review. Renewable and Sustainable Energy Reviews, 34, 273–299. https://doi.org/10.1016/j.rser.2014.03.017
Devecioğlu, A. G., Yaman, U., & Oruç, V. (2024). Determination of optimum insulation thickness and economic analysis for heat pump application in different degree day regions of Turkey. Dicle University Journal of Engineering, 15(4), 863–871. https://doi.org/10.24012/dumf.1547522
Dikici, A., & Kocagül, M. (2019). Experimental comparison of EPS, XPS and rock wool insulation materials used in thermal insulation. Fırat Üniversitesi Mühendislik Bilimleri Dergisi, 31(1), 129–136. https://izlik.org/JA87TR46KK
Dombaycı, Ö. A. (2007). The environmental impact of optimum insulation thickness for external walls of buildings. Building and Environment, 42(11), 3855–3859. https://doi.org/10.1016/j.buildenv.2006.10.054
Domínguez-Muñoz, F., Anderson, B., Cejudo-López, J. M., & Carrillo-Andrés, A. (2010). Uncertainty in the thermal conductivity of insulation materials. Energy and Buildings, 42(11), 2159–2168. https://doi.org/10.1016/j.enbuild.2010.07.006
Fan, J. L., Zeng, B., Hu, J.-W., Liu, Y., & Zhang, X. (2021). Exploring the spatiotemporal characteristics of heating and cooling degree-day in China 1951–2016. International Journal of Global Warming, 23(4), 415–428. https://doi.org/10.1504/IJGW.2021.114346
Geliş, K., & Yeşildal, F. (2020). Determination of minimum insulation thickness by changing the thermal conductivity coefficient in the case of using classical and modern building elements. Gümüşhane University Journal of Science and Technology, 10(4), 869–877. https://doi.org/10.17714/gumusfenbil.725909
Gnip, I., Vėjelis, S., & Vaitkus, S. (2012). Thermal conductivity of expanded polystyrene (EPS) at 10°C and its conversion to temperatures within interval from 0 to 50°C. Energy and Buildings, 52, 107–111. https://doi.org/10.1016/j.enbuild.2012.05.029
Huang, H., Zhou, Y., Huang, R., Wu, H., Sun, Y., Huang, G., & Xu, T. (2020). Optimum insulation thicknesses and energy conservation of building thermal insulation materials in Chinese zone of humid subtropical climate. Sustainable Cities and Society, 52, Article 101840. https://doi.org/10.1016/j.scs.2019.101840
Işık, E., & Tuğan, V. (2017). The calculation of the optimum wall thickness for heat isolation in the provinces of Tunceli, Hakkâri, and Kars. International Journal of Pure and Applied Sciences, 3(2), 50–57. https://doi.org/10.29132/ijpas.328883
Kayfeci, M., Keçebaş, A., & Gedik, E. (2013). Determination of optimum insulation thickness of external walls with two different methods in cooling applications. Applied Thermal Engineering, 50(1), 217–224. https://doi.org/10.1016/j.applthermaleng.2012.06.031
Mihlayanlar, E., & Meral, S. (2023). Energy efficiency renovation and EKB application in existing buildings. Kırklareli University Journal of Engineering and Science, 9(2), 478–497. https://doi.org/10.34186/klujes.1379762
Ministry of Energy and Natural Resources. (2024). Energy statistics of Türkiye 2024.
Omer, S. A., Riffat, S. B., & Qiu, G. (2007). Thermal insulations for hot water cylinders: A review and a conceptual evaluation. Building Services Engineering Research and Technology, 28(3), 275–293. https://doi.org/10.1177/0143624406075269
Özbek, K., Geliş, K., & Özyurt, Ö. (2022). Optimization of external wall insulation thickness in buildings using response surface methodology. International Journal of Energy and Environmental Engineering, 13(4), 1367–1381. https://doi.org/10.1007/s40095-022-00490-9
Özel, M. (2013). Determination of optimum insulation thickness based on cooling transmission load for building walls in a hot climate. Energy Conversion and Management, 66, 106–114. https://doi.org/10.1016/j.enconman.2012.10.002
Özkan, D. B., & Onan, C. (2011). Optimization of insulation thickness for different glazing areas in buildings for various climatic regions in Turkey. Applied Energy, 88(4), 1331–1342. https://doi.org/10.1016/j.apenergy.2010.10.025
Tsoka, S. (2023). Evaluating the impact of urban microclimate on buildings’ heating and cooling energy demand using a co-simulation approach. Atmosphere, 14(4), Article 652. https://doi.org/10.3390/atmos14040652
Turkish Standards Institution. (2025). TS 825: Thermal insulation requirements for buildings. Retrieved January 15, 2026, from https://intweb.tse.org.tr/standard/standard/Standard.aspx?081118051115108051104119110104055048065082077055103076076056084117109066085066115043115081085119079047082043074082121122119112116043048121100117084084071057079101119101115057089080103107079117057079074083088112082116116121078079116066073114110117117089100114082067051105076122087067069074054120122051075056116055104109120054085100057116054103070110090081104071097101078070089073065101081053110068084110075110122089114117047076054116051108106118068119061061
Uçar, A., & Balo, F. (2010). Determination of the energy savings and the optimum insulation thickness in the four different insulated exterior walls. Renewable Energy, 35(1), 88–94. https://doi.org/10.1016/j.renene.2009.07.009
Uçar, A., & Dumrul, M. U. (2019). Determination of optimum insulation thickness and energy saving analysis according to heating and cooling loads for exterior walls of a house in Malatya. European Journal of Science and Technology, 16, 740–749. https://doi.org/10.31590/ejosat.586176
Uçar, A. (2024). Optimization of insulation thickness of walls and roofs using energy, exergy, economic and environmental (4E) analyses. Journal of Mechanical Engineering and Sciences, 18(1), 9959–9975. https://doi.org/10.15282/jmes.18.1.2024.12.0787
Uygunoğlu, T., & Keçebaş, A. (2011). LCC analysis for energy-saving in residential buildings with different types of construction masonry blocks. Energy and Buildings, 43(9), 2077–2085. https://doi.org/10.1016/j.enbuild.2011.04.011
Vujnović, N., Vidak, D., Jakšić, F., Kedmenec, Ž., Dović, D., & Horvat, I. (2021). Differences in calculations of annual heating and cooling energy need carried out by modified simple hourly method and dynamic simulations. Transactions of FAMENA, 45(SI-1), 35–48. https://doi.org/10.21278/TOF.45SI1007021
Yu, J., Yang, C., Tian, L., & Liao, D. (2009). A study on optimum insulation thicknesses of external walls in hot summer and cold winter zone of China. Applied Energy, 86(11), 2520–2529. https://doi.org/10.1016/j.apenergy.2009.03.010
Yüce, B. E., & Acar, M. C. (2021). Analysis of optimum insulation thickness and energy savings for different fuels and wall components in Bitlis province. Bitlis Eren University Journal of Science, 10(4), 1426–1434. https://doi.org/10.17798/bitlisfen.959930

Details

Primary Language

English

Subjects

Energy Efficiency, Construction Materials, Mechanical Engineering (Other)

Journal Section

Research Article

Authors

Meryem Coşkunsu ^*
0009-0000-2853-7967
Türkiye

Murat Cuma
0000-0001-7202-0957
Türkiye

Emel Çelik
0009-0007-1589-9089
Türkiye

Yusuf Çay
0000-0003-4007-6168
Türkiye

Publication Date

October 23, 2026

Submission Date

January 15, 2026

Acceptance Date

September 2, 2026

Published in Issue

Year 2026 Volume: 14 Number: 4

DOI

https://doi.org/10.29130/dubited.1864176

IZ

https://izlik.org/JA95JF58DE

APA

Coşkunsu, M., Cuma, M., Çelik, E., & Çay, Y. (2026). Energy and Economic Analysis of Optimum Insulation Thickness for Exterior Walls in Sakarya Province. Duzce University Journal of Science and Technology, 14(4), 1176-1189. https://doi.org/10.29130/dubited.1864176

AMA

1.Coşkunsu M, Cuma M, Çelik E, Çay Y. Energy and Economic Analysis of Optimum Insulation Thickness for Exterior Walls in Sakarya Province. DUBİTED. 2026;14(4):1176-1189. doi:10.29130/dubited.1864176

Chicago

Coşkunsu, Meryem, Murat Cuma, Emel Çelik, and Yusuf Çay. 2026. “Energy and Economic Analysis of Optimum Insulation Thickness for Exterior Walls in Sakarya Province”. Duzce University Journal of Science and Technology 14 (4): 1176-89. https://doi.org/10.29130/dubited.1864176.

EndNote

Coşkunsu M, Cuma M, Çelik E, Çay Y (October 1, 2026) Energy and Economic Analysis of Optimum Insulation Thickness for Exterior Walls in Sakarya Province. Duzce University Journal of Science and Technology 14 4 1176–1189.

IEEE

[1]M. Coşkunsu, M. Cuma, E. Çelik, and Y. Çay, “Energy and Economic Analysis of Optimum Insulation Thickness for Exterior Walls in Sakarya Province”, DUBİTED, vol. 14, no. 4, pp. 1176–1189, Oct. 2026, doi: 10.29130/dubited.1864176.

ISNAD

Coşkunsu, Meryem - Cuma, Murat - Çelik, Emel - Çay, Yusuf. “Energy and Economic Analysis of Optimum Insulation Thickness for Exterior Walls in Sakarya Province”. Duzce University Journal of Science and Technology 14/4 (October 1, 2026): 1176-1189. https://doi.org/10.29130/dubited.1864176.

JAMA

1.Coşkunsu M, Cuma M, Çelik E, Çay Y. Energy and Economic Analysis of Optimum Insulation Thickness for Exterior Walls in Sakarya Province. DUBİTED. 2026;14:1176–1189.

MLA

Coşkunsu, Meryem, et al. “Energy and Economic Analysis of Optimum Insulation Thickness for Exterior Walls in Sakarya Province”. Duzce University Journal of Science and Technology, vol. 14, no. 4, Oct. 2026, pp. 1176-89, doi:10.29130/dubited.1864176.

Vancouver

1.Meryem Coşkunsu, Murat Cuma, Emel Çelik, Yusuf Çay. Energy and Economic Analysis of Optimum Insulation Thickness for Exterior Walls in Sakarya Province. DUBİTED. 2026 Oct. 1;14(4):1176-89. doi:10.29130/dubited.1864176

Abstract

Keywords

Energy and Economic Analysis of Optimum Insulation Thickness for Exterior Walls in Sakarya Province

Abstract

Keywords

Supporting Institution

Ethical Statement

Thanks

References

Details

Primary Language

Subjects

Journal Section

Authors

Publication Date

Submission Date

Acceptance Date

Published in Issue

DOI

IZ

Cite