Due to some health and breathing issues we ordered 2 of these units and received them last week.  For the past year I've battled allergies, bronchitis and now the onset of occasional asthma issues.  Since plugging these guys in we can tell a noticeable difference in the inside air at home both day and night.  My 2. 5 yr old grandbaby also has some congestion issues going on and this has cleaned our up air up seemingly well.  We do have 3 dogs as well as live in an area pretty rich in pollen often throughout the year.  This past 5 days I've had better, more restful sleep, without so much night-time coughing and congestion.  I also have a humidifier since March of this year trying to help, but the purifier seems to be making a world of difference.....at least in my world.