[boondocks95]

I already know my flex needs to be changed because its old, deteriorated on the inside, etc. Occasionally until he last month I get a faint musky odor coming thru the vents. I usually only notice if when the heat kicks on, but today its also when the AC blows. It's not all the time tho. I do have a mold problem in my bathroom that we will be remediating in the spring. I was wondering if this black/gray stuff is just dirt or if its mold inside the flex? (See pic.) I assumed it was dirt but trying to determine the cause of the stinch.

The HVAC installers I spoke with said it was burn-off when because the heat had been on a few weeks ago. But obviously that's not it.

 

[beenthere]

Nothing in the pic looks like mold from here.

 

[boondocks95]

Thanks! I had intended to replace the flex this passed weekend but a family emergency has prolonged that for a few weeks. I attempted to cover the holes with foil tape but some of them are just awful. They are all terribly nasty. I even found broken demo debris in one. Obviously I'm only replacing the flex. The trunk hopefully isn't a concern. I believe it's fully metal. Should I be super concerned about air quality until I can replace! They've been this way for at least six months I believe, maybe since we purchased the home four years ago. We also have a toddler in the home.