Volumetric Monitoring and Modeling of Indoor Air and Pollutant Dispersion by the Use of 3D Particle Tracking Velocimetry

Human beings spend most of their lifetime indoors. Monitoring indoor airflow in buildings is a matter of health safety, and energy savings. Regarding health safety it is proven that exposure to aerosol pollution like walls and painting material residues, gasses emitted through cooking and heating with biomass fuel, or agricultural residues can result in aggravated health damages for the occupants. In the same time, too high air exchange rates increase the heating demand in temperate and cold climates. On both cases it is important to control the mixing of the air and the pollutant dispersion to ensure the occupants’ comfort and productivity. Before monitoring air mixing and pollutants dispersion in rooms, one has to decide whether qualitative or quantitative data is needed. Qualitative measurements only allow recovering the trajectory and patterns of the airflow in rooms. This is usually done by the use of tracer gasses like fumes, incense, or neutrally buoyant particles with suitable light sources. For more precise purposes such as comfort parameters measurements (Fanger, 1970) or validation of CFD modeling, one need to get access to quantitative data. Quantitative air measurement techniques may be divided into Eulerian and Lagrangian techniques. Eulerian techniques measure flow velocity at one or several fixed locations at a time, as a man on a bridge measures the velocity of a water stream going by below him. Eulerian methods used for indoor applications include hot wire and hot film anemometry, pulsed wire anemometry, ion anemometry, laser Doppler velocimetry, laser 2-focus velocimetry, particle image velocimetry (PIV), stereoscopic PIV, tomographic PIV and holographic PIV. Depending on the technique, the result can be a one, two, or threedimension velocity vector or velocity vector field. But Eulerian techniques suffer from two major drawbacks: First, many are intrusive since they involve probes which are inserted in the measured flow. The probes not only change the flow by their mere presence, but they also disturb the measure. For example, though hot