AC Duct sweating

[jonticchi]

Hello, I have owned this house for many years and unfortunately I have not addressed this sooner. My AC is in the attic and all the ducts go down to the 2nd and 1st floor. The ducts that go to the !st floor go from attic down the back wall of the house inside the wall and make a 90 degree turn into the living area. Looking up at the ceiling are stains from the duct sweating. More so with high humity and outside their is a over hang. so if you take the vinyl sofite off you can see the duct out side. so at all the vents in the middle of the living area there are stains closer to the wall outside. I have painted with Kiltz water sealer and has helped a bit. Now the vents that are in the kitchen have started. so on top of the kitchen is the roof . The vent goes from the attic down a floor to a small attic above the kitchen. and of course to a couple of vents. Is there anything i can do? There is no humidifier on the Unit not sure if I should put fans in the attics. I had a new roof installed 2 years ago and it has the vents on the peak of the roof to vent out the attics. I have to spackle two seams in the kitchen and paint this winter, I would like to prevent this from happening again. What should i do???

[Admin]

Any duct installed in an unconditioned space should be insulated to prevent condensation.