YAŞAM DÖNEMİ MALİYETLEMESİ YAKLAŞIMI İLE MEVCUT BİNALARDA OPTİMUM YALITIM KALINLIĞININ BELİRLENMESİ

Abstract

Enerji kullanımının ve enerji fiyatlarının devamlı bir şekilde artması birçok araştırmacıyı bir sürdürülebilir kalkınma aracı olan enerji tasarrufu stratejilerine yönlendirmiştir. Mevcut binaların dış cephelerinin yalıtımı enerji verimliliğinin arttırılması için yaygın ve etkin bir yöntemdir. Yalıtım uygulamaları bir ilk yatırım maliyeti gerektirmesine karşın binanın gelecek senelerde daha az enerji harcamasını sağlar. Bu açıdan, özellikle gelişmekte olan ülkelerde, mali açıdan uygun bir yalıtım kalınlığının bulunması önem arz etmektedir. Bu çalışmanın amacı bir temsili bina yaklaşımı kullanarak mevcut binalar için optimum yalıtım kalınlığının belirlenmesidir. Bu amaçla, temsili bir mevcut bina için tavana 15 cm taş yünü ve dış duvarlara değişen kalınlıklarda genleşmiş polistiren (EPS) yalıtımı uygulanmıştır. Çeşitli EPS kalınlıkları (1 cm’den 20 cm’e) yalıtım alternatifleri olarak analiz edilmiştir. Binanın yıllık enerji gereksinimi dinamik analiz yapan ısı dengesi yöntemi ile belirlenmiştir. Yaşam dönemi maliyetlemesi analizi gerçekleştirilerek hangi alternatifin en iyi ekonomik sonucu verdiği belirlenmiştir. Optimum yalıtım kalınlıkları çeşitli iklim bölgeleri için farklı iskonto ve enflasyon oranlarını içeren birtakım senaryolar göz önünde bulundurularak elde edilmiştir. Sonuçlar ulusal standardın mevcut yalıtım limitlerinin yetersiz olduğunu göstermektedir. Optimum yalıtım kalınlıklarının ulusal standartta belirtilen sınırlayıcı değerlerden bariz bir şekilde daha büyük oldukları anlaşılmıştır. Bu verimsizliğin giderilmesi amacıyla standarttaki sınırlayıcı ısı transfer katsayılarının azaltılarak enerji verimliliğinin arttırılması önerilmektedir.

Keywords

• Optimum yalıtım kalınlığı
• ısı yalıtımı gereksinimleri
• mevcut binaların enerji verimliliği
• yaşam dönemi maliyetlemesi

A LIFE CYCLE COSTING APPROACH TO DETERMINE THE OPTIMUM INSULATION THICKNESS OF EXISTING BUILDINGS

Abstract

The ongoing global increase of energy prices and energy use has directed many researchers to study energy conservation strategies as an instrument of sustainable development. A common yet effective strategy is to insulate the exterior envelope of existing buildings in an attempt to improve energy efficiency. While an insulation application requires an initial investment, it helps the building to spend less energy during its operation. In order to sustain feasibility, it is crucial to find an insulation thickness that is cost-effective and especially applicable in developing countries. The objective of this study is to determine the optimum insulation thickness for existing buildings by using a representative building approach. For this purpose, insulation alternatives including 15 cm stone wool on ceilings and expanded polystyrene (EPS) on exterior walls at varying thicknesses were applied on a representative existing building. A variety of EPS thicknesses (from 1 cm to 20 cm) were analyzed as alternatives for the insulation application. Annual energy requirement of the building was calculated by the heat balance method by conducting a dynamic analysis. Life cycle costing (LCC) analysis was performed to find out which alternative results in the best economical outcome. The optimum insulation thicknesses were obtained for various climate regions by considering a number of scenarios with different discount and inflation rates. The results demonstrated the inadequacy of the national regulation’s current insulation limits, as it was observed that the optimum insulation thicknesses were significantly greater than the limiting values in the national standard. To overcome this inadequacy, it is suggested to effectively improve energy efficiency by lowering the limiting heat transfer coefficients in the standard.

Keywords

• Optimum insulation thickness
• thermal insulation requirements
• energy efficiency of existing buildings
• life cycle costing

References

1. Asdrubali, F., D'Alessandro, F. and Schiavoni, S., 2015, A Review of Unconventional Sustainable Building Insulation Materials, Sustainable Mater. Technol., 4, 1-17.
2. Ashouri, M., Astaraei, F. R., Ghasempour, R., Ahmadi, M. H. and Feidt, M., 2016, Optimum Insulation Thickness Determination of a Building Wall Using Exergetic Life Cycle Assessment, Appl. Therm. Eng., 106, 307-315.
3. ASHRAE, 2013, 2013 ASHRAE Handbook Fundamentals, American Society of Heating, Refrigerating and Air-Conditioning Engineers, ISBN: 978-1-936504-46-6, Atlanta, GA 30329.
4. ASHRAE, 1997, 1997 ASHRAE Handbook Fundamentals, American Society of Heating, Refrigerating and Air-Conditioning Engineers, ISBN: 188-3-413443, Atlanta, GA 30329.
5. Axaopoulos, I., Axaopoulos, P. and Gelegenis, J., 2014, Optimum Insulation Thickness for External Walls on Different Orientations Considering the Speed and Direction of the Wind, Appl. Energy, 117, 167-175.
6. Briga-Sa, A., Nascimento, D., Teixeira, N., Pinto, J., Caldeira, F., Varum, H. and Paiva, A., 2013, Textile Waste as an Alternative Thermal Insulation Building Material Solution, Constr. Build. Mater., 38, 155-160.
7. Cristina, B., Paolo, C. S. and Spigliantini, G., 2017, Evaluation of Refurbishment Alternatives for an Italian Vernacular Building Considering Architectural Heritage, Energy Efficiency and Costs, Energy Procedia, 133, 401-411.
8. Cuce, E., Cuce, P. M., Wood, C. J. and Riffat, S. B., 2014, Optimizing Insulation Thickness and Analysing Environmental Impacts of Aerogel-Based Thermal Superinsulation in Buildings, Energy Build., 77, 28-39.

9. Daouas, N., 2011, A Study on Optimum Insulation Thickness in Walls and Energy Savings in Tunusian Builings Based on Analytical Calculation of Cooling and Heating Transmission Loads, Appl. Energy, 88, 156-164.
10. Dylewski, R. and Adamczyk, J., 2011, Economic and Environmental Benefits of Thermal Insulation of Building External Walls, Build. Environ., 46, 2615-2623.
11. Hasan, A., 1999, Optimizing Insulation Thickness for Buildings Using Life Cycle Cost, Appl. Energy, 63, 115-124.
12. IEO, 2013, International Energy Outlook, Technical Report, U.S. Energy Information Administration.
13. Kaya, M., Firat, I. and Comakli, O., 2016, Economic Analysis of Effect on Energy Saving of Thermal Insulation at Buildings in Erzincan Province, J. Therm. Sci. Technol., 36(1), 47-55.
14. Kaynakli, O., 2013, Optimum Thermal Insulation Thicknesses and Payback Periods for Building Walls in Turkey, J. Therm. Sci. Technol., 33(2), 45-55.
15. Kon, O. and Yuksel, B., 2016, Optimum Insulation Thickness Calculated by Measuring of Roof Floor and Exterior Walls in Buildings Used for Different Purposes, J. Therm. Sci. Technol., 36(1), 17-27.
16. Lucchi, E., Tabak, M. and Troi, A., 2017, The “Cost Optimality” Approach for the Internal Insulation of Historic Buildings, Energy Procedia, 133, 412-423.
17. Maleviti, E., Wehrmeyer, W. and Mulugetta, Y., 2013, An Emprical Assessment to Express the Variability of Buildings’ Energy Consumption, Int. J. Energy Optim. Eng., 2(3), 55-67.
18. Miguel, C., Labandeira, X. and Löschel, A., 2015, Frontiers in the Economics of Energy Efficiency, Energy Econ., 52, S1-S4.
19. Mishra, S., Usmani, J. A. and Varshney, S., 2012, Energy Saving Analysis in Building Walls Through Thermal Insulation System, Int. J. Eng. Res. Appl., 2(5), 128-135.
20. Morales, S. P., Munoz, P., Juarez, M. C., Mendivil, M. A. and Munoz, L., 2016, Energy Efficiency in Buildings: Study of Single-Leaf Walls Made with Clay Bricks, J. Energy Eng., 142(1), 04015011.
21. Nematchoua, M. K., Raminosoa, C. R., Mamiharijaona, R., René, T., Orosa, J. A., Elvis, W. and Meukam, P., 2015, Study of the Economical and Optimum Thermal Insulation Thickness for Buildings in a Wet and Hot Tropical Climate: Case of Cameroon, Renewable Sustainable Energy Rev., 50, 1192-1202.
22. Nematchoua, M. K., Ricciardi, P., Reiter, S. and Yvon, A., 2017, A Comparative Study on Optimum Insulation Thickness of Walls and Energy Savings in Equatorial and Tropical Climate, Int. J. Sustainable Built Environ., 6(1), 170-182.
23. Nikoofard, S., Ugursal, I. and Beauseleil-Morrison, I., 2015, Economic Analysis of Energy Upgrades Based on Tolerable Capital Cost, J. Energy Eng., 141(3), 06014002.
24. Pedersen, C. O., Fisher, D. E. and Liesen, R. J., 1997, Development of a Heat Balance Procedure for Calculating Cooling Loads, ASHRAE Trans., 103(2), 459-468.
25. Ramos, A., Gago, A., Labanderia, X. and Linares, P., 2015, The Role of Information for Energy Efficiency in the Residential Sector, Energy Econ., 52, S17-S29.
26. Serrano, S., Urge-Vorsatz, D., Barreneche, C., Palacios, A. and Cabeza, L. F., 2017, Heating and Cooling Energy Trends and Drivers in Europe, Energy, 119, 425-434.
27. Spitler Jeffrey D., 2013, Load Calculation Application Manual, ASHRAE and Oklahoma State University, Atalanta.
28. Sundaram, A. S. and Bhaskaran, A., 2014, Optimum Insulation Thickness of Walls for Energy-Saving in Hot Regions of India, Int. J. Sustainable Energy, 33(1), 213-226.
29. Turkish Standards Institution, 2008, Thermal Insulation Requirements for Buildings, Turkish Standard 825, Official Gazette Number 27019, (In Turkish).
30. Yigit, S. and Ozorhon, B., 2018, A Simulation-Based Optimization Method for Designing Energy Efficient Buildings, Energy Build., 178, 216-227.
31. Yildiz, Y., Ozbalta, T. G. and Eltez, A., 2014, Energy-Saving Retrofitting of Houses in Cold Climates, J. Therm. Eng., 34(1), 53-61.
32. Yu, J., Yang, C., Tian, L. and Liao, D., 2009, A Study on Optimum Insulation Thicknesses of External Walls in Hot Summer and Cold Winter Zone of China, Appl. Energy, 86, 2520-2529.