I have a unit that has a two ton gas furnace and two ton evap coil that are approximately 15 yrs old. The condenser is a two and a half ton. The problem is a great amount of moisture is leaking out of each of the ducts and ruining the ceiling. The unit is in the hallway and the ducts go up in the attic and are metal but have good insulation. The unit has zero superheat and is a mess . Oh yea the condenser is reted foe 13 seer however the coil has a fixed orifice device. I think I should increase the coil and furnace to 2.5 tons to match the condenser since it is fairly new and hopefully cure the problem any suggestions would be helpfull.