Location
Depending on where you plan to put your air purifier, you may be able to narrow down your options. The best purifier for your needs is determined by the amount of space you want to cleanse and the types of particles you want to eliminate. Portable air purifiers are meant to clean a single room, but whole-house air purifiers are more expensive and can clean a wider area.
Allergic reactions
Your allergies may also influence which purifier is ideal for you, mainly if a particular model covers them.
HEPA and other types of filters
Allergy air purifiers should at the very least have a HEPA filter. Nonetheless, most versions come with numerous filters, including a HEPA filter. Purifiers with more than one filter may have as many as two pre-filters and a third carbon filter on rare occasions.