Best Smart Air Purifiers of 2025: Tested and Reviewed by Experts

An important consideration for air purifiers is filter replacement. Some models require frequent replacement of expensive filters, which can cost you hundreds of dollars each year.

Before purchasing a model, consider the type of replacement filters you will need, how much they will cost and whether you can afford to replace them as required. Otherwise, choosing not to replace the filter as recommended may reduce the effectiveness of the air purifier. After all, they are capturing and trapping harmful particles, such as mold spores and bacteria.

Some air purifiers have washable filters, making maintenance easier. However, the most effective air purifiers include HEPA filters and carbon filters that need to be replaced. You can find the manufacturer’s requirements in the instructions for use.

Some modern purifiers have indicator lights that warn you when it’s time to change the filter. As a general rule, plan to replace carbon air filters every three months and other filters every six months.