I am writing here because I am in desperate need of advice. My uncle and I installed a central AC system about 3 years ago in my unfinished attic of my ranch style house. AC only not for heat. The metal ductwork is all insulated with 1 inch foiled covering and the flex duct is insulated.
The first January after it was installed I noticed a leak on the drywall from above. I thought it was an ice dam from the old roof but I could not find anything. The 2nd year - nothing. This (the third year) it leaked again. Upon investigation the AC trunk had water in the end and was dripping. The flex ducts also have a very significant amount of water in them. Both years that it leaked were in January near a cold spell. When I took off the end cap I found that the water was about 1/2 inch thick and frozen but beginning to melt - thus the ceiling leak. Both years I did a good deal of cooking in December (holidays). I keep my heat relatively low in the day when I am not home about 61F and relatively low when I am home about 65F. I have checked the main condensate line and it is flowing - but a little slowly. The flex ducts come off the trunk slope down and then back up again to go to the boots and then into the house. I do not cook that much in the house but my wife and I shower daily and have tea - for moisture components.
Any ideas why this is happening and how I can stop this madness? The flex ducts need to be drained they are so full. My attic has 1 gable vent and 2 roof top vents, no ridge vent. It is fairly cold up there and well ventilated.
I close all of my registers in the fall and open them in the cooling season. I also put a piece of sheetmetal to block the large return in the hallway.
I could really use some good advice on this one. One HVAC guy told me that it was warm moist air from the house rising up and condensing. Could this really cause that much water - enough to put about 16oz in each flex duct? What should I do - HELP!!!