Help~ Smell coming out of vents from my neighbor - Townhouse
We live in a townhouse. Our new neighbor really likes using air diffusers that spread very very strong odor. Somehow and someway, the odor got into my house through vents. But not just vents, I think the smell also came out of the staircase and a cabinet in the bathroom that is near to the staircase. It doesn't happen all the time. What happened was that our vents could suddenly blow out the odor and kept having it for many hours but, sometimes, only lasted for 20, 30 mins. It was very random. It seems like it was because my neighbor turned on his exhaust fan, or something like that. It is really really annoying when my house is full of smell coming from somewhere else and totally out of my control.
I've tried to reach out to a few HVAC contractors but they said they wouldn't be able to do anything with it because they are just selling AC or heating system... Does anyone know what kind of experts can actually fix this problem?
Thank you so much!