Newbie question - smoke leaking through vents.

[patrickleland]

Hi, I need a nudge in the right direction.

I live in an apt complex built in the 70s that was recently flipped into condos. I had my HVAC replaced about 18 months ago. I am on the second floor of a two-story building and there is a vent that runs from the first floor HVAC closet, goes into the attic/atmosphere. There is a vent that comes out of the top of my HVAC unit and joins this main vent.

Recently, a new tenant moved in downstairs and he smokes inside. When he smokes, I can smell smoke coming from my HVAC closet. I sealed all the visible seams on the vent tubing with a putty-type of sealant and with metallic duct tape, and the smell still reoccurs.

The smell is most prevalent when I am not running my HVAC unit at all (windows open because it's a nice day, at night the temps are comfortable without HVAC assistance, etc.), so now I suspect that some sort of negative pressure is sucking the smoke through my HVAC unit into my condo.

Is this prognosis feasible? If so, what are potential solutions? What else could be going on?

Thanks in advance!

[skippedover]

Smoke unfortunately is simply an man made component that's added to the air. It disperses to try and fill the entire enclosure with smoke. It is unlikely you'll be able to overcome this with any degree of ease. The building is constructed like a human body, with a skeleton (the building frame) on the inside and the 'skin' on the visible parts of the room. Just as you cannot see your bones, yet they are all connected together, such is the construction of your home. All the framework is interconnected and smoke/air will travel readily between units and especially where there is a 'chimney effect' of warmer air rising into cooler air. There are some electronic air cleaners that could be installed in your HVAC system to help alleviate the smoke smell from your unit. You'll want to shop carefully for such products as most (despite manufacturer disclaimers) require professional cleaning to keep the operating properly. Simply putting the cells in the dishwasher no more cleans them than soap and water used to clean an oven! There are some models that have replaceable elements and those are to what I would suggest you direct your attention.