My (2) BlueAir Pure 211 Plus units have been performing perfectly in my home for almost 2 years now. I have them running 24/7. And I really notice the air is not so fresh if they have been switched off for any period of time. During the California wildfires last year and this year the air outside has been ghastly! Staying indoors with the filters on makes everything fine. Very grateful to have such a dependable product. The filters are insanely easy to change. It easy to see if the dust has accumulated on the outside liners and easy to swap out for a fresh one. Thanks for making a perfect product!