Ive ran into this problem before. Ive pulled evap coil and cleaned with chemical first. this has happened a few times with different custiomers. If the water is still dripping from the middle of the coil after cleaning and lowering fan speed, the problem is what is described as a dry spot in the coil. two causes are a defect in the copper or aluminum in a specific spot or a restricted cell inside the evaporator. to check for a restricted cell would be to disconnect the fan motor and turn on the a/c. you should see the coil frosting up. if water persistantly dripps from the evap coil you should replace evap coil. doesnt happen often but it does happen. if its a defect in the metal it should have been happening since day one. if its a restricted coil (cell), this problem might not present itself for some time after installation
