I have a 12yr old Goodman 4 ton unit with a bad compressor. My house is approximately 1900sq. feet cape cod. We live in central NC. I have had several vendors out for quotes on replacing the complete system. My Trane vendor did a load calculation that recommended only a 2.5ton unit. The other vendors questioned the need for 4ton, most quoted a 3.5ton unit. My questions are:
1. Are load calculations accurate?
2. Can my 4ton just be replaced by a 2.5ton unit with little duct work?
3. Will the 2.5 ton unit adequately heat/cool my home?