The non-uniform behaviour of the air inside a room, which is important in comfort analysis, can be evaluated by zonal models. While not as fine-grained as CFD simulation, they do give useful information about temperature and moisture distributions that is not available from lumped-parameter models. Therefore, we have developed a tool, called SimSPARK, to automatically build dynamic zonal simulations of a building zone. Its model library includes different models to describe heat and moisture transfers across the building zone envelope, with two of them taking into account moisture adsorption/desorption by building materials. To illustrate the applicability of this tool, we compare two zonal models including adsorption and desorption processes with one that ignores these phenomena, in a ventilated room modelled using 27 cells. The results indicate that adsorption/ desorption by building materials does affect indoor air behaviour in a hot and humid climate.