Radiative Properties of Expanded Polystyrene Foams

Expanded polystyrene foams are one of the most widely used materials for a building’s thermal insulation. Owing to their very low density, a substantial proportion of the heat transfer is due to thermal radiation propagating through their porous structure. In order to envisage an optimization of their thermal performances, an accurate modeling of their radiative behavior is required. However, the previous studies on this subject used several drastic simplifications regarding their radiative behavior (optically thick material) or their porous morphology (homogeneous cellular material, dodecahedral cells). In this study, we propose a more accurate model based on a detailed representation of their complex morphology allowing us to predict their entire monochromatic radiative properties. We investigated the influence of the different structural parameters on these properties. We checked the validity of our model by comparing the spectral hemispherical reflectance and transmittance measured on slabs of foam samples with values predicted by our model. A good accordance was found globally.