Paper Title
A Study on the Parameters Affecting Insulation Thickness on External Wall of Buildings

Abstract
There are many parameters affecting the optimum thermal insulation thickness on building external walls such as heating/cooling loads, wall structure, properties of the insulation material and also economic parameters (inflation rate, discount rate, lifetime and energy costs). This study focused on an investigation of the effects of these parameters on the optimum thermal insulation thickness and payback periods. To determine the optimum thickness and payback period, an economic model based on life-cycle cost analysis was used. As a result, the optimum thermal insulation thickness increased with increasing the heating and cooling energy requirements, the lifetime of the building and energy costs. However, the thickness decreased with increasing the total wall resistance. Keywords- Insulation thickness, space heating-cooling, energy costs