We have a leaking coil. About 9 years old, Trane 4ton. The tech noticed the suction line was spliced when installed new, but they spliced a length of 5/8 with 7/8. The whole run is about 80' with about half at 5/8". There is another problem in that the condensers were installed flip-flopped, so we've been running a 3ton condenser on a 4ton coil with 5/8 and 7/8 suction line for years. Add to that duct and plenum problems and you get the jist of my angst. I'm assuming the line set should be replaced,(?) it's just a bear to get to and running outside would look horrible even using a downspout or conduit. The condenser will either get replaced or swapped with the other which is 3 1/2 ton which has been running on a 3ton coil. Welcome to metro Atlanta new construction problems...