Thermal Insulation Thickness Optimization Based on Energy Cost for Internally Insulated Walls

In this study, optimization of the thermal insulation thickness, which minimizes the energy cost of the internally insulated wall application, was carried out for the province of Ankara. Ankara is located in the third region according to the degree-day classification in Turkey. Optimum insulation thickness, payback period and saving amount were calculated by utilizing life cycle cost analysis. The optimum insulation thickness for the internally insulated wall application, in which XPS is used as the insulation material, was determined as 0.039 m. The payback period for the optimum insulation thickness determined was 13.52 years and the savings amount was approximately 5.97 USD/m².