Thermal Conductivity of Mineral Wool Materials Partially Saturated by Water

Abstract

The thermal conductivity of several types of mineral wool-based materials, namely, materials with hydrophobic admixtures, hydrophilic admixtures, and without any admixtures are measured as a function of moisture content from the dry state to the partially water saturated state. An impulse technique is employed for the measurements using both surface and needle probes. The data are analyzed using the Bruggeman effective media concept for different shapes of inclusions and Wiener’s basic formulas. It is found that for most materials, the experimental data for thermal conductivity in the range of low moisture content are close to the lower Wiener’s bound but in the range of higher moisture content the data are close to the upper Wiener’s bound.