I was not expecting much from from the shark clean sense air purifier max but I am actually surprised at how well it works , I got this during the wildfires from Canada, for 3/4 days outside was so Smokey , we live in PA , there was warning’s to stay indoors because of the air quality, when I plugged this in it started working instantly , it took a while for it to reach 100% but we could definitely tell the difference, as soon as you opens our door the burning smell was awful but inside no smell at all , the fan was on a lot during that time , it worked so well I bought a second one for my sons bedroom because he has allergies and asthma and I can definitely see a difference with my son , he does not cough as much and has been having less flare ups , I am so happy with this