This is an estimate for a 3 1/2 Ton AC and Air handler system with ductwork. Customer chose the Carrier 16 Seer with the X-13 Airhandler. We will be replacing all equipment, lineset, emergency drain pan, plenums and redoing returns. We are to make the 14x24 returns into 14x30 returns and make the return ducts 16â€. We will also be adjusting the layout of the supply ducts. Existing duct work will be used, just adjusting tap sizes and adding a couple wyes to free up plenum space. Warranties: 10 year parts 10 year coils 10 year compressor 1 year labor