Hi, I am in the process of replacing the 27 year old GE 8 ton split unit on my 4800 sq ft home (2400 upstairs, 2400 downstairs). I had a Trane FSR come out and evaluate my situation and here is what he recommends I go with. A Trane 7.5 Ton dual circuit air handler fed by two staged 4-ton single phase condensers. I don't have 3 phase electrical supplie available which is why the two 4-ton units. My ducting system feeds both upstairs and downstairs concurrently. Does this sound logical to the experts? I have two sons that work for Trane and I am getting a good deal on the equipment so I prefer to stay with Trane. Your comments, suggestions are appreciated,