2100 sq ft. 3.5 ton unit. 18 months old. all of the bedrooms are much hotter than the rest of the house. Also, I'm not positive the ductwork looks quite right in the attic. I'm going to try to figure out how I can post pictures of the duct work. One of the flex lines is coming apart from the main duct and it appears to be very wet and there is water that has settled in the flex. All the flex runs are just sitting on the floor of the attic on top of the insulation. I am by far not an expert but something just doesn't seem right. Also, is there a max distance that a flex line should be used to go to a vent. There is one that looks like the line is 25 to 28 feet from main trunk.