Indoor air quality needs
If you’re someone who suffers from allergies, consider choosing a machine designed for allergy relief—these models include HEPA filters which can remove 99.97% of most airborne particles sized 0.3 microns or larger (for reference, the average cross-section of a human hair is 50 microns).
If you suffer from asthma, consider purchasing an asthma air purifier that includes a HEPA filter as well as odor and chemical filtration. If you’re sensitive to chemicals, go for an air purifier that has multiple chemical sensitivities (MCS). These contain more powerful filtration for odors and chemicals than other models and are often manufactured with materials that will not off-gas chemicals into the air.