A model for predicting heat, air and moisture transfer through fibrous materials

A precise hygrothermal model is essential to predict the energy performance of building envelopes providing coupled transport of mass (moisture and air) and heat through porous elements, considering phase change and all heat transfer modes, including the radiative transfer through fibrous materials. Therefore, a new mathematical model, called CAR-HAM (Conductive, Advective, and Radiative Heat, Air and Moisture), is proposed to include the radiative transfer equation to calculate the thermal radiation effects within the porous materials to be taken into account in the energy balance. The moisture and the energy conservation equations are simultaneously solved using a fully implicit scheme and the MTDMA algorithm. The comparison of the proposed model considering some case studies such as attic insulation, bar drying, convection and high humidity (rain load) - showed a good agreement with experimental data available in the literature.