Monozone modelisation of natural ventilation with ducts.

European project pr EN13465 from CEN TC 156/WG2/AH4 gives a monozone model for airflow calculations in dwellings. In order to apply it to natural ventilation systems with adjacent ducts used in dwellings in France, we need to address several issues. First, in adjacent ducts, airflows at each level depend on pressions in the different dwellings. We have to solve by iteration the balanced equation proposed in AH4. Then, cowls and roof outlet performances as well as the wind-pressure coefficient on the roof must be known. Finally, for dimensioning purposes, airflows must be calculated including the air transfer between rooms. As the dwelling is considered in monozone, taking it directly into account is impossible and the study considered it as an additional pressure drop.