La deposizione di particelle in ambienti chiusi

A few rooms of historic buildings (in Venice, Padua, Vicenza, and Rome) were examined in order to check the indoor microclimate and the spectral distribution of the concentration of the suspended particulate matter. Measurements were carried out by the diffusion of a laser beam as a function of the size of the particles and their concentration. Different situations were detected. The Brownian deposition can be reduced by lowering the room temperature; thermophoresis may be reduced when the wall surface is warmer than the air; diffusiophoresis and Stefan deposition are reduced by avoiding humidity cycles. The role of carpets and the presence of visitors are also discussed.