YAŞAM DÖNEMİ MALİYETLEMESİ YAKLAŞIMI İLE MEVCUT BİNALARDA OPTİMUM YALITIM KALINLIĞININ BELİRLENMESİ

Öz

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.

Anahtar Kelimeler

• 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

Öz

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.

Anahtar Kelimeler

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

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