I’m currently replacing my old AC ducts on my 70s ranch home(1800 Square feet under AC) in South Florida. I currently have have two units at each end of the house. I have a 3 ton unit supplying three bedrooms living and dining area. On the other side of the house I have a 2 ton that supplies the family room and the kitchen( 444 ft.²) and on the other side the3 ton unit supplies the bedrooms, hallway, dining room and living room(1180 ft.²) My contractor says that it will be best to reconfigure the duct system and have it supplied by just one 4 ton unit. I’ve also had People in the business that advised me to either keep both units the way it is and that with the new ducts and Insulation the house will call just fine. Others tell me to switch both units around and have the 2 ton unit supply the bedrooms and a 3 ton unit supply the rest of the living areas. My original contractor says that keeping both units will be too much AC for the square footage which is a total of 1700 ft.² under AC and that they will not be efficient in removing the humidity. To make things even worse I’ve had contractors tell me that I need a 5 ton unit for my home and I’ve had others that say that a 4 ton is what I need and when I look online the calculations usually say a ton per 500 ft.² which will mean that a 3 ton will be enough. Would love to know anyone else’s input. Thank you.