Installed this two weeks ago in a 'florida' room with a 'damp' smell.  At the same time - our cat was 'living' in that room due to a house full of movers and contractors... so there were liter and food smells as well.  We were running both a ceiling fan AND an 'in wall' AC unit - full tilt.  After turning on this air purifier (which btw sat behind the tv and very very quiet) - the following morning there was a Startling improvement in the smell in the room.  Shocked my very skeptical husband as well.   AND we found quickly we could just skip the noisy AC unit - even turn off the ceiling fan - as this circulated the air nicely - while improving air quality.