Air purifiers can clean hard surfaces. But not all types of air purifiers do this effectively. Different kinds of air purifier technology work differently. For example, Air Oasis HEPA filters use a fine mesh to trap small particles, down to 0.1 microns in size. This removes them from the air. Other forms of air purification, such as air ionization, change contaminants on a molecular level, even on surfaces, because the ions land on and interact with surface borne contaminants just as they do in the air.