The paper presents data on the removal efficiencies of two commercially available console air cleaners, one equipped with a high efficiency filter, the other with an electrostatic precipitator (ESP). Room air particle size distribution is examined in detail, both before and during use, and time-slice data are given on the effect on overall concentration of the operation of the units. The data show that both the filter-equipped unit and the ESP unit are highly efficiency in removing particles with diameters of 1.0 micrometer and larger, the size range of pollens and spores, but less efficient at removing smaller particles. The paper concludes with a brief discussion of the cost/benefits of each unit.