Effects of temperature, porosity and moisture content on the effective thermal conductivity of glass wool material were studied. The material used is glass wool of different apparent thicknesses. Measurements of the porosity of a thermal insulating material were carried out using different techniques. It was found that the effective thermal conductivity increases with increasing the average temperature, the moisture content and the apparent density of the specimen within the given range ( 16 b100 kg/m3 ), and with decreasing the porosity. In the present work correlations of the measured effective thermal conductivity as a dependent parameter and the average temperature, porosity and moisture content as independent parameters were obtained.