Experimental Study Abour How the Thermal Plume Affects the Air Quality a Person Breathes

The Personal Micro Environment (PME) depends directly on the heat transfer in the surrounding environment. For the displacement ventilation systems the convective transport mechanism, which is found in the thermal plume around a person, influences the human exposure to pollutants. The aim of this research is to increase the knowledge of how the thermal plume generated by a person affects the PME and therefore the concentration of contaminants in the inhalation area. An experimental study in a displacement ventilation room was carried out. Experiments were developed in a full scale test chamber 4.10 m (length), 3.2 m (width), 2.7 m (height). The incoming air is distributed through a wall-mounted displacement diffuser. A breathing thermal manikin exhaling through the mouth and inhaling through the nose was used. A tracer gas, N2O, was used to simulate the gaseous substances, which might be considered as biological contaminants, exhaled by the manikin. The manikin was operated in three different heat fluxes with a value of: 0W, 94 W and 120 W. During the experiments six concentration probes were situated in the room. Three concentration tubes were fixed on the surface of the manikin at three different heights: hips, chest and nose (inhalation). The three other tubes were situated in a vertical line at 0.50 m from the manikin and at the same three heights. The results show the highest concentration of contaminants around the manikin when the manikin heat load is fixed to 0W. However, the concentration is significantly reduced in the case with 120 W, especially in the breathing area