I heard today that this is becoming a common problem:
Dryer vents clogging up quickly due to condensation inside the uninsulated duct. The clog is occurring up near the roof termination point.
I guess this could occur on ones that run horizontal to a wall too.
I’m going to start recommending these ducts be insulated starting with a predrywall I did today.
I have started seeing more insulated condensate drain pipes in attics too (new homes). With the larger homes and owners that run the A/C a lot, there can be a lot of dripping condensation off these pipes into the attic insulation/sheetrock.