A heat and mass transfer model was developed to predict, during the drying of a food processing plant, the evolution of the water mass, wet surface, air temperature and relative humidity. The model was previously validated by comparing the predictions with the experimental results obtained in a food processing plant. Then, this model was coupled with a microbiological model to predict the fate of Listeria monocytogenes (growth or inactivation) at different locations in the plant (floor, wall and equipment). Simulations were carried out for blown air at 50%, 68% and 85% relative humidity in order to study the influence of air dehumidification in the plant on the drying rate and on the evolution of the microbial load. It was found that bacteria are more likely to develop on equipment when the drying time is longer. A technical solution involving heating of the equipment was proposed and the impact on the wet surface and the evolution of the microbial load was presented.