Optimum Insulation Thickness for the Exterior Walls of Buildings in Turkey Based on Different Materials, Energy Sources and Climate Regions

Abstract

Thermal insulation improves the strength and longevity of buildings by reducing energy consumption, and as a related result, improved energy use. The selection of insulation material is governed by important parameters, including the average outdoor air temperature, the thermal conductivity of the buildings and the cost of the insulation material. Increases in the thickness of the insulation material will gradually decrease the energy consumption for heating; however, the insulation thickness has an optimum value that minimises the total investment cost, and determination of this optimum value is critical for economic analysis. In this paper, a life-cycle cost analysis is presented to show the optimum insulation thickness, energy savings over a lifetime of 15 years and payback periods for six different fuels and insulation materials for four cities in Turkey selected from climate regions identified by the Turkish Thermal Insulation Standard (TS 825). Muğla (1st region), Kocaeli (2nd region), Ankara (3rd region) and Ardahan (4th region) were selected for analysis of a sandwich-type wall constructed from the following six insulation materials: extruded polystyrene, expanded polystyrene, glass wool, rock wool, polyisocyanurate and polyurethane. The calculations were also made on the basis of six different fuels, such as motorin, natural gas, propane (LPG), electricity, coal (imported), and fuel-oil No. 4. As a consequence, results demonstated that the optimum insulation thickness vary between 2.8 cm and 45.1 cm, with energy savings between 16.4 ₺/m² and 479 ₺/m², and payback periods fluctuating between 0.078 and 0.860 years, depending on the city, the insulation material, and the cost of fuel.

Keywords

• energy saving,optimum insulation thickness,payback period,climate region,life-cycle cost

References

1. A. Aytac & U.T. Aksoy, Enerji Tasarrufu iç ve Dış Duvarlarda Optimum Yalıtım Kalınlığı ve Isıtma Maliyeti ilişkisi, J. Gazi Univ. Fac. Eng. Archit., vol. 21, pp. 753–758, 2006.
2. T. Keskin, "Enerji Verimliliği Kanunu ve Uygulama Süreci", Mühendis ve Makina vol. 569, pp. 106-112, 2007.
3. N. Evcil, "Isı İzolasyonu ve Dış Duvarların Enerji Etkin Yenilenmesi", Yüksek Lisans Tezi, İstanbul Teknik Üniversitesi Fen Bilimleri Enstitüsü, İstanbul, 2000.
4. İzocam Tic. San. A.Ş., Isı-Teknik-Ses-Yangın Yalıtımı, İzocam Ticaret ve Sanayi A.Ş. Yayınları, İstanbul, 2002.
5. A. Dombaycı, M. Gölcü & Y. Pancar, "Optimization of insulation thickness forexternal walls using different energy-sources", Applied Energy, vol. 83, pp. 921–928, 2006.
6. K. Çomaklı & B. Yüksel, "Optimum insulation thickness of external walls for energy saving", Applied Thermal Engineering, vol. 23, pp. 473–479, 2003.
7. A. Bolattürk, "Optimum insulation thickness for building walls with respect to cooling and heating degree-hours in the warmest region of Turkey", Building and Environment, vol. 43, pp. 1055-1064, 2008.
8. O. Kaynaklı, "A study on residential heating energy requirement and optimum insulation thickness", Renewable Energy, vol. 33, pp. 1164-1172, 2008.

9. O. Kaynaklı & R. Yamankaradeniz, "Isıtma Süreci ve Optimum Yalıtım Kalınlığı Hesabı", VIII. Ulusal Tesisat Mühendisliği Kongresi, pp. 187-195, 2007.
10. M. Gölcü, A. Dombaycı & S. Abalı, "Denizli için Optimum Yalıtım Kalınlığının Enerji Tasarrufuna Etkisi ve Sonuçları", Gazi Üniversitesi Müh. Mim. Fak.Dergisi, vol. 21, pp. 639-644, 2006.
11. A. Uçar & F. Balo, "Determination of the energy savings and the optimum insulation thickness in the four different insulated exterior walls", Renewable Energy, vol. 35, pp. 88-94, 2010.
12. O. Kon & B. Yüksel, "Konut Dışı Kompleks Yapılar için Optimum Yalıtım Kalınlığı", 18. Ulusal Isı Bilimi ve Tekniği Kongresi, ULIBTK’11, Zonguldak, pp. 604-610, (07-10 Eylül 2011).
13. D. B. Özkan & C. Onan, "Optimization of insulation thickness for different glazing areas in buildings for various climatic regions in Turkey", Applied Energy, vol. 88, pp. 1331-1342, 2011.
14. T.M.I. Mahlia, B. N. Taufiq & H. H. Masjuki, "Correlation between thermal conductivity and the thickness of selected insulation materials for building Wall", Energy and Buildings, vol. 39, pp. 182-187, 2007.
15. N. A. Kürekçi, "Determination of optimum insulation thickness for building walls by using heating and cooling degree-day values of all Turkey’s provincial centers", Energy and Buildings, vol. 118, pp. 197-213, 2016.
16. A. Ulaş, "Binalarda TS 825 Hesap Yöntemine Göre Isı Kaybı, Yakıt Tüketimi, Karbondioksit Emisyonu Hesabı ve Maliyet Analizi", Gazi Üniversitesi Fen Bilimleri Enstitüsü, Yüksek Lisans Tezi, Ankara, 2010.
17. A. Hasan, "Optimizing Insulation Thickness for Buildings Using Life Cycle Cost", Applied Energy, vol. 63, pp. 115-124, 1999.
18. M. Ozel & K. Pihtili, "Determination of optimum insulation thickness by using heating and cooling degree-day values", J. Eng. Nat. Sci, vol. 26, pp. 191-197, 2008.
19. A. Gürel & A. Daşdemir, "Türkiye’nin Dört Farklı İklim Bölgesinde Isıtma ve Soğutma Yükleri İçin Optimum Yalıtım Kalınlıklarının Belirlenmesi", Erciyes Üniversitesi Fen Bilimleri Enstitüsü Dergisi, vol. 27, pp. 346-352, 2011.
20. H. Sarak & A. Satman, "The degree-day method to estimate the residential heating natural gas consumption in Turkey: a case study", Energy, vol. 28, pp. 929-939, 2003.
21. N. Sisman, E. Kahya, N. Aras & H. Aras, "Determination of optimum insulation thicknesses of the external walls and roof (ceiling) for Turkey's different degree-day regions", Energy Policy, vol. 35, pp. 5151-5155, 2007.
22. A. E. Gürel & A. Daşdemir, "Türkiye’nin dört farklı iklim bölgesinde ısıtma ve soğutma yükleri için optimum yalıtım kalınlıklarının belirlenmesi", Erciyes Üniversitesi Fen Bilimleri Enstitüsü Dergisi, vol. 27, pp. 346-352, 2016.
23. N. A. Kurekci, "Determination of optimum insulation thickness for building walls by using heating and cooling degree-day values of all Turkey’s provincial centers", Energy and Buildings, vol. 118, pp. 197-213, 2016.
24. TSE (Turkish Standards Institution). TS 825: Thermal Insulation in Buildings; 1998.
25. N. Daouas, Z. Hassen & H. B. Aissia, "Analytical period solution for the study of thermal performance and optimum insulation thickness of building walls in Tunisia", Appl Thermal Eng, vol. 30, pp. 319–326, 2010.
26. M. Tolun, "Farklı derece-gün bölgeleri için yalıtım probleminin incelenmesi", PhD Thesis. Enerji Enstitüsü, 2017.
27. A. Aytaç & U. T. Aksoy, "Enerji Tasarrufu İçin Dış Duvarlarda Optimum Yalıtım Kalınlığı ve Isıtma Maliyeti İlişkisi", Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi, vol. 21, pp. 753-758, 2006.