Daily I know someone who smokes a couple oneys of chronic and blows it in the vent that sucks the air in his bathroom (the shower fan) He's probably been doing this for about a year since he moved in. Today, they posted a sign on his building (with 10-15 or so more apartments) that said: NOTICE Someone in this building has been smoking marijuana and a neighbor can smell it. Please stop use immediately Or we will notify the authorities. This has got him worried, but it doesn't make sense. Why now? Is it possible that the vents carry the scent to another apartment? He lives on the second story. Maybe it simply was someone else in the apartments? He's worried about smoking in there anymore, and that's one of the only ways he ever can.