Optimum thermal insulation thicknesses and payback periods for building walls in Turkey

Abstract

In this study, a procedure for optimizing the thermal insulation thickness for external walls has been presented and the optimum insulation thicknesses, energy savings and payback periods based on heating and cooling energy requirements have been calculated separately and also together for each city in Turkey. By considering the energy costs for heating and cooling, insulation material and installation costs, the optimum insulation thicknesses have been determined on the basis of life-cycle cost analysis over a building lifetime of 20 years. The results shows that the optimum thermal insulation thicknesses for only heating energy vary between 4.7 and 16.6 cm, vary between 0 and 3.8 cm for only cooling energy, and vary between 5.7 and 16.6 cm for total annual (heating + cooling) energy depending on the city. On the other hand, the payback periods in Turkey vary between 3.85 and 16.25 years when considering the total annual energy requirements. Furthermore, a parametric analysis has been also performed in order to investigate the effective parameters on the optimum insulation thickness and energy savings.