Air Purifiers
Most air purifiers have a filter indicator (often a light) that alerts you when the filter should be checked and possibly replaced. Though you can simply wipe down most prefilters, the main HEPA filter should be replaced about every six to 12 months, or as your manual advises. We factor this expense—new filters can cost between $50 and $100 or more annually—into the annual costs listed in our air purifier ratings.
Keep in mind that some newer air purifiers will notify you when it’s time to change a filter based on how much you’ve used the unit, and others base their alert on a set number of hours.
“Most filter replacement interval suggestions are based around an assumption of 24/7 use, so if you are using yours less frequently, it may be worth inspecting your filters to see if it’s time for a replacement,” says CR’s Misha Kollontai, who oversees our air purifier tests.
For more on air purifiers, see our air purifier ratings and buying guide.
