Battling Cigarette Smoke
We live in a rowhouse with exposed brick and the smell of our neighbors smoking seeps in through the walls.  I bought this to combine with my larger Guardian air filter to help combat it.  So far it seems to be helping, though a few more would probably increase the success.  It is louder than I expected, so we might keep it on at night and when we are gone and unplug when we are home.  having several on at once might make it sound like an airport runway.
Rating: 4 stars