A new method for measurement of air change rate based on indoor PM2.5 removal

摘要

Outdoor PM2.5 easily flows into indoor and seriously influences indoor air quality due to its characteristics of flow, diffusion and penetration. It is a proper gas' tracer similar to CO2 to study building ventilation. Therefore, in this paper, a model for calculating air change rates by removing indoor PM2.5 was deduced. Also, some factors influencing the air change rate were qualitatively analyzed and the expression of possible air change rate error was given. The comparison between the results from PM2.5 removal method and the data from CO2 decay method validated the model. The relative error between the results of the two methods is less than 10%. On the basis of validating the model, this paper presented the research of air change rates in ten naturally ventilated house rooms in three Chinese cities. It is found that the rooms with the ventilation rates of 1.15-6.75m(3)/h/person have inadequate ventilation.