An Investigation into the Effective Gaseous Thermal Conductivity of Fibrous Insulation Materials

The goal of this research is to determine how the effective gaseous thermal conductivity in fibrous insulation materials varies with pressure and gaseous composition and if the chosen testing method is appropriate for such measurements. A comparative cut-bar methodology has been used to measure the effective thermal conductivity of FiberForm®. The selected samples were exposed to different gaseous environments composed of air and N₂. Along with varying gases, these samples were tested over a wide range of pressures from 2–760 Torr. It was found that as the pressure increased, the measured thermal conductivity also increased in each gas. These thermal conductivity results approximately followed the expected trends predicted by kinetic theory.