Numerical modelling of unsteady humidity transport and accumulation in walls

The purpose of the work is the determination of unsteady variation of the moisture content in the walls. The mathematical model is based on humidity transport equations in porous media. The humidity transport takes place as a result of the presence of both moisture content and vapour pressure differences. Using the proposed mathematical model, a computer program was developed in EES (Engineering Equations Solver). Numerical simulations were made for an office room, considering interior walls containing a gypsum board layer. The results showed that humidity absorbtion-desorbtion in an interior wall depends on: wall structure, materials properties, inlet air parameters, initial relative air humidity in the wall and room occupancy.