Really need some expert advice. In the process of replacing 2 complete systems in our 2 story house. Total sq. ft is 3215, lower is 1814, upper is 1401. Current systems are 18 plus years old, Carrier 2 1/2 ton each. Both air handlers are located in a mechanical room on the 2nd floor and all duct work runs through our attics.

Thought I was going about this the right way, read a lot on here. Had a company come out and perform an energy survey to include a Man J, blower door, duct testing, etc. Hers score of 114 with recommendations to seal ducts, add insulation and various other minor things. They also provided a couple of system recommendations. Also had 3 other companies come out and provide recommendations. All companies have excellent reputations and carry a variety of manufacturers. 3 Man J's came up with cooling load requirements of between 44,000 and 52,000.

So here is the dilemma, each company come up with completely different recommendations. Company A: 2 1/2 ton up and down, B: 2 1/2 down 3 up, C: 2 down 2 1/2 up, D: 2 1/2 down 2 up. Company D also made a strong recommendation to do a single 5 ton zoned system using a Carrier 2 stage, variable speed unit.

After all this I am even more confused as what to do.