How much maintenance is required for the air filters?
This varies from air purifier to air purifier. Most air purifiers have two to four filters. For the majority of air purifiers, filters should be cleaned occasionally and changed every six to eight months for optimum results. However, some models such as the Friedrich C-90B Electrostatic Air Cleaner feature permanent air filters that never need changing. Others have a combination of washable and replaceable air filters. To help maintain the life of your air purifier, many models include filter indicator lights. Read product descriptions and manufacturer literature to determine if the air purifier you are interested in has a filter indicator light.
