I live in a 1987 colonial with siding and brick. About three weeks ago my family woke up choking at 5:00 am from a dirty/ mildew type smell. We identified it as coming from the chimney and had the chimney resealed and all all cracks cemented.
Then the smell morphed and was dry and dirty/dusty almost cigarette. When the system is off, we smell it in the return vents. When the air is off, we can smell it coming out of the supply.
It moves around the house but seems constant by the front foyer and the upstairs hallways. We have had the ductwork cleaned, the coils on the hvac cleaned and an ionizer installed in the hvac. We have had two separate companies test for mold and they have found nothing.
We have a hospital grade filtration system. We are going nuts and can't live there because my throat starts to close. We're ready to just walk away at this point but it would crush us financially. Any advice?