I moved into a duplex a year ago. I new the person in the other unit smokes. Also the person who had lived in my unit also smoked, so when the A/C would come on I would get the smell of cigarette smoke. I figured it was because the former occupant smoked and it would eventualy go away, not so. Every time the blower comes I get cigarette smoke smell in my unit. I suspect the cold retun is hooked up to the other unit. Is that possible?

I've looked at the cold air return vents, one in the bedroom and one in the livingroom. Neither is connected to the furnace. The bedroom duct empties into the laundry room (as an opening near the ceiling), where both furnaces and hot water heaters are also located. All are gas fired.

The return from the living room also empties into the basement, one can look up and see the opening.

The landlord has been hesitant about fixing the problem, and he used to be in the business.

I would move but can't afford to.

Is this violating any codes?

Thanks for any help.