Numerical simulation on factors influencing indoor PM2.5 concentration

Simulates and analyses the influences of various factors on the indoor PM2.5 concentration by Fluent software, including the filtration efficiency, air exchange rate, initial concentration of indoor PM2.5 and air distribution modes in an air conditioning room with the central air supply. The results show that compared with that of the up-supply and down-return system, the air flow velocity of the sideward air supply and return system is faster, and its diffusion range is greater in the same time, resulting the increase of the indoor pollution area. When the outdoor air pollution is serious, the increase of the air exchange rate is not conducive to improve the indoor air quality.Indoor initial concentration is proportional to mixed concentration,and the higher the initial concentration of indoor PM2.5, the more difficult the indoor pollutant dilution.The effect of the air filter efficiency on mixed PM2.5 concentration is greater than that of the initial PM2.5 concentration on the concentration of the mixture. The air filter efficiency and indoor PM2.5 concentration are linear relationship.