Originally Posted by yuri
THe only filter that blocks smoke is a carbon type and they are rare and hard to find and don't last long. Some buildings have a central exhaust for the hallways and building. I would talk to the landlord and see if anything can be done. If you interfere with it they can blame you. Does your building have no smoking rules, you should not have to put up with others smoke, talk to the landlord about it.
It's not a building. It's a row of condo's, which resembles what people consider townhouses, so there is no landlord. We are all responsible for our own central air units (each condo unit has its own central air unit). So I kinda on my own here. So far my only solution is to block the return, which is fine until I need to turn on the heat.
EDIT: would I damage anything if I cut some kind of carbon filter and taped it to the inside of the return grille?