A simplified approach of air infiltration in multizone buildings.

The specific value of different flows resulting from air exchanges between rooms or with the outside is not always important. An extensive model is not suitable when only estimations or tendencies have to be drawn (very time consuming). So we developed a simplified infiltration model for predicting airflows in single rooms and between different zones of a building. We integrated this model into a building transient thermal simulation program set up to a micro-computer system. So as to obtain this model, we used simplified assumptions. We planned those simplifications into two directions : - separate study of the actions induced by wind and stack effect, - sepatate study of mass and heat transfers. In this way, our approach consists in searching for a satisfying compromise between an appreciable saving of time and consistent results. The model is devised as follows : - a transitional step where the ingoing airflows are calculated once for all under the successive agency of wind and stack effect. this step leads to the storage of the different flows into matrices reflecting both effects. - a connecting step where airflows resulting from wind and stack effect are combined.