This study presents a zonal model used for predicting the air temperature distribution inside a room. This model is original in the calculation of mass air flows between two zones. To do so, we distinguish zones where the momentum is small and for which we calculate the flow rates with the aid of a pressure field, and the driving zones described using appropriate specific flow laws. A comparison between experimental results and those obtained with the model proves that they are fully consistent with each other. This allows us to consider the integration of this type of model into a general building thermal code.