CADR is a common rating you might find for portable air purifiers, and it references the clean air delivery rate. Types of Air Purifiers and FiltersThe best portable air purifiers all work on the same principle, but vary in type and capacity. Absorbent Air PurifiersUsing activated charcoal or carbon, these air purifiers trap unwanted odors, air pollutants, and volatile organic compounds (VOCs). How to Find the Right Air Purifier for YouTo select the best air purifier for your home, we suggest considering the following:Choose an air purifier that's the right size for your space. Some air purifiers come with other perks like air quality monitors, change filter indicator lights, and smart technology.