Modeling and Database Development of Conductive and Apparent Thermal Conductivity of Moist Insulation Materials

Abstract

Computer simulation and modeling of coupled heat and moisture transfer are becoming increasingly significant for accurate calculations of heat and moisture transfer. However, to solve their equations, the true component, λ, of apparent thermal conductivity, λapp, as a function of temperature, moisture content, and material structure is required. An approach to the development of a comprehensive database for λ is discussed. Its key feature is demonstrated by the development of a theoretical model for λ and λ app of two common building insulation materials — expanded polystyrene insulation and highly porous calcium silicate — for a wide range of temperature and moisture conditions.