Assessing natural urban ventilation through an integrated model.

The paper presents further then an integrated model the supporting methodology that allowsto assess natural urban ventilation conditions both outside and inside constructions.Though some particular aspects arid procedures can be complex and time consuming thegeneral structure is quite simple:1. to establish wind regimes as a boundary condition - information can come from windmeasurements at undisturbed areas Like airports;2. to integrate these regimes within the site - using numerical models to transfer information tothe site;3. to assess local wind velocities and pressures - promoting wind tunnel tests over physicalmodels reproducing at a convenient scale its main characteristics;4, to estimate ventilation rates - outside, from measurements, and inside, computing internalflow rates as dictated by both external and internal conditions.Results can go from drawing general patterns of ground level winds, allowing to assessexternal ventilation and comfort conditions for pedestrians, to a computation of the flows andair proprieties, promoted inside a room taking into account small heat sources and sinks aswell as the external conditions imposed by the wind.