Ah, good find, ny! I hate cigarette smoke smell above just about anything else. We lived upstairs in an old historic home in Ohio for awhile, and the widow lady downstairs smoked like a chimney. We had to keep towels stuffed under the door to the upstairs to keep the smell out. Fortunately, that seemed to be the only infiltration point.
I hope the air purifier helps! Be sure to report back.
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow