I live in a condo (new construction) and we have several problems that the contractor still cannot understand: dust coming from nowhere, cold air coming in even from the smallest cracks in the windows, cold floor near dryer exhaust, etc. I tried looking up, and it always comes up that there might be a negative pressure problem.

This week-end, I disconnected the HRV and tried to find where the negative pressure could come from. I found air tends to go towards the laundry room. I did not find where it is, but there is definitely something there that is sucking air... but with no inlet.

Is that supposed to be? This fan would be running 24/7 with no inlet, I'm assuming this could be the cause for the negative pressure situation, am I right?