Daffy Duck HVAC design in NC

[Sure,Not]

I have a 2550 sq. foot home. 1 1/2 stories. 1750 down and 800 up. The floor plan is pretty much open other than the master bedroom and bath. The HVAC contractor installed a 2 ton HVAC down and 2.5 up.

Downstairs has 13 supply vents. 11 6" inch pipes and 2 8" inch pipes. Return is 25 x 20 with a 12 pipe. Supply is also a 12" pipe.

Upstairs has 2.5 tons supplying 5 supply vents (6" pipe) and a 20x20 return (12" pipe).

[The Daring Dufas]

Does the upstairs have a lot of or big windows. I repaired the upstairs heat pump for a customer and his upstairs unit is larger because of large windows thus more heat load.

TDD