We exam new and outdated machines. When retesting our existing air-purifier picks, we consider 4 measurements—two using the outdated filters and two employing new filters—to learn how (or even though) their general performance changed over time. And we only live with them. We station our picks in many homes, generally https://top10bookmark.com/story16854417/the-ultimate-guide-to-shark-air-purifier-1200-sq-ft