Abstract
Air cleaning characteristics in a turbulent flow type cleanroom in which particle generation sources were present, was examined experimentally. Based on the results of these experiments, evaluation method of air cleaning ability and its definition are proposed. The main factors influencing air cleanliness are the number of air change and particle generation rate. For each experimental case, the cleanroom had the muximum particle generation rate of 400000 P/(min 10m^2) and other conditions, such as number of air change, which were fixed in correspondence with the cleanliness class 8, 7, 6 in JIS B9920. The values of air cleanliness in the experiments were below the limits of the cleanliness class 8, 7, 6. It is proposed that air cleaning ability should be defined as the ratio of the representative maximum value, whichever is greater, either the maximum of the average particle concentrations measured at the sampling locations or the upper confidence limit of the mean of these averages in the cleanroom having a constant particle generation rate, to the class limit.
