It works!  We had a bad smell in our basement hall.  Don't know if there was some bathroom overflow accident before we got the house, but it smelled vaguely like sewer even though the septic all checked out.  A mouse had died behind the wall or above the ceiling a while back and we had tried everything to freshen: shampooed the carpet and freshened the air with febreeze and even scrubbed the walls and baseboards.  Before knocking off the textured ceiling which may be where the smell resided we tried the air purifier and it seems to work!  We don't have a lot of ventilation down there I guess and it seemed to do the trick...definitely more than a simple fan. It smells like...nothing.  Exactly what I want.