Comparison of Different Insulation Materials with Thermal Conductivity Coefficients Based on Density and Temperature for Two Climate Zones

Abstract

Abstract The selection of the insulation material and the determination of the optimum insulation thickness are very important in terms of energy saving and providing thermal comfort conditions. There are many studies in the literature to determine the optimum insulation thickness. In these studies, the thermal conductivity coefficient (k) of the insulation material is taken directly from the standardized tables and the optimum insulation thickness calculation is made. In real applications, the k value of the insulation material varies depending on the production conditions, density and temperature. For this reason, the density of the insulation material and the operating temperature should be taken into account in determining the optimum insulation thickness. In this study, Expanded Polystyrene (EPS), Extrude Polystyrene (XPS), glass wool and rock wool with different densities were used as insulation materials, coal and natural gas were used as fuel. A comparison was made for the provinces of Konya and Sivas, which are in the 3rd and 4th climate zones in Turkey, using the degree-day method depending on energy costs, and the insulation thicknesses were determined as a function of density and temperature. As a result of the calculations for the k, value of the insulating material for the province of Konya, which is in the 3rd climate zone, the optimum insulation thickness was established as 0,076 m for EPS with a density of 30 kg/m3, 0,037 m for XPS with a density of 30 kg/m3, 0,082 m for glass wool with a density of 100 kg/m3, 0,051 m for rock wool with a density of 150 kg/m3. Likewise, when coal is used as fuel, the optimum insulation thicknesses for EPS, XPS, glass wool and rock wool are 0,092, 0,061, 0,104, 0,078 respectively. As a result of the calculations for the k, value of the insulating material for the province of Sivas, which is in the 4th climate zone, the optimum insulation thickness was established as 0,086 m for EPS with a density of 30 kg/m3, 0,044 m for XPS with a density of 30 kg/m3, 0,092 m for glass wool with a density of 100 kg/m3, 0,058 m for rock wool with a density of 150 kg/m3. Likewise, when coal is used as fuel, the optimum insulation thicknesses for EPS, XPS, glass wool and rock wool are 0,098, 0,069, 0,106, 0,081 respectively. When the insulation materials are compared, although the unit price of XPS material is higher, its optimum thickness is lower than other insulation materials for all situations due to its low thermal conductivity.