Air flow through building slits and components.

Pressure models require a good knowledge of the pressure distribution around the building and a precise description of air paths. The hydrodynamic behavior of these connections is usually reduced to an empirical power law Q = K.dP(n) with n equal to 0.5 for a turbulent flow and 1.0 for a laminar one. We present three levels of approach to improve our knowledge of the flow behavior of building components. First, we propose a new light experimental tool to determine the on site flow behavior of building elements. Second, we present the flow behavior of innovative air inlets developed in France and from on-site feedback, we suggest design improvments. Finally, we expose an extensive set of experiments on calibrated slits in the 0-100 Pa range and compare our results with other experiments. We point out that the fixed power law is not well suited in the low AP (0-20) Pa range which is the range of interest for building ventilation.