A new process of air purification has been developed and studied experimentally (Agranovski et al. 1999). This process is based on passing air through a filter immersed in liquid. It leads to the formation of bubbles within the filter as the carrier gas passes through and thus provides alternate mechanisms for the removal of aerosols. It was identified (Agranovski et al. 1999) that for relatively large particles (0.3-2.7 w m) the efficiency of the filter utilized in wet filtration is higher than for dry filtration. In the current paper, experiments are described that investigate the performance of the technology for particles in the size range of 0.03 to 2.7 w m, to identify the importance of an alternative mechanism of purification (diffusion). Also, 9 different filters were employed to compare the efficiencies of the wet and dry filtration for different applications of the technology.