Numerical Simulation Of Indoor Microbes Distribution In Different Ventilated Rooms

Indoor environment is the most significant place for person, with the majority of time is spent within it, statistically, so the quality of indoor environment has an remarkable impact on human health. Indoor environmental quality is influenced by a lot of factors such as indoor air quality, lighting, temperature, humidity and so on, in which indoor air quality is bound with human health directly and permanently, particularly the airborne microbe by comparison. Therefore, the study of removing of indoor airborne microbe is critical.Firstly, the sources of indoor airborne microbes were analyzed, within which indoor and outdoor sources are the main contributors. Indoor sources including human body, accumulated dust on surface, air-conditioning system and so on., outdoor sources are concerned with main source is fresh air and infiltration of wind through windows or doors. The species and characteristics of indoor airborne microbes were introduced and the living environment and the pathogenesis of each main microbe were analyzed, it showed that the formation of aerosol particle was the most important stage in microbial contaminant impact.Then, indoor airborne microbes'movements (including infiltration, deposition, transformation, etc.) were analyzed, and on the base of mass conservation, the distribution model of airborne microbes and its influence factors were proposed theoretically, in this paper.With regard to the methods of removing indoor airborne microbes, the removing and diluting effects of the supply air in air-conditioning systems were analyzed in this paper. The distribution of airborne microbes in 2.5μm and 10μm in three cases-①indoor sources;②outdoor sources;③indoor sources and outdoor sources under three different air supply condition were analyzed respectively and contrasted, numerically.The results showed that when the grain diameter size of airborne microbes was 2.5μm, the"Up-supply Down-return"style was the best way to remove the airborne microbes, while when the grain diameter size was 10μm, the main part of the airborne microbes were from the supply air, that is, outdoor sources, and the best way would be portable air-contioning, while the portable air-condition was more effective in local region and more feeble considering the whole condition in the room compared with the two others.Therefore, the grain diameter size should be given priority when evaluating the removing of airborne microbes in different air supply methods. The demand of the whole room and local region should be weighted before selecting portable air-conditioning.The research in this paper could be used to improve the air-conditioning systems and the indoor air quality, and the concentration of the indoor airborne microbes also could be evaluated by the model.