Expert: Dan Griffin - 9/5/2011

Question
Can the venting in a condo development (i.e. bathroom venting, range hoods, HVAC) be interconnected between units, per the building code?  Because the unit below me just sealed their floors, and the solvent smell is prevalent in my unit in the bathroom, near my range hood, and near a few vents from where the units are adjacent.  In addition, I have smelled cigarette smoke in the same bathroom before--possibly from my neighbor smoking in their bathroom with the vent on?  I assumed that the building code would forbid this kind of venting...

Answer
Scott, it would be quite unusual to have common venting even on one unit.  This is done on commercial buildings quite often with an exhaust fan on the roof and ducting to individual uses.  This cannot be done on range hoods which often require fire suppression and grease interceptors/cleaning ports.  HVAC fresh air intakes are quite separate.

What I suspect is that the hoods and exhausts are not ducted to the outside or the ducting has been damaged.  Some smells are pervasive such as solvent odors in paint and sealers, and can well overpower a small vent fan.  If the venting all was routed to the soffit ( quite possible) there could be a back draft of odors, though if your fans are on, they would not back draft.

A more thorough answer would require onsite investigation.  YOu might consider using a smoke generator to see where your vents are exiting.