Thanks for answering my questions.
So, it seems your system is able to deliver on capacity in both heating and cooling modes when there are no component or functional issues with the system. Is that correct?
Now, another question. Did Unico make your entire system, or just the air handlers? Is the heat pump/chiller itself made by Unico, or others? Is this system a high velocity duct arrangement, with small ducts and outlets?
Building Physics Rule #1: Hot flows to cold.
Building Physics Rule #2: Higher air pressure moves toward lower air pressure
Building Physics Rule #3: Higher moisture concentration moves toward lower moisture concentration.
All Unico system
Yes, this is a Unico Unichiller, all unico parts including the high velocity 2 inch ductwork/outlets.
I talked to Mitchell, our second HVAC guy tonight, and he said the 5 Ton unit is certainly NOT oversized, and that the Unico rep he talked to said it might be okay to add the basement to the system, if all zones weren't demanding a lot of cooling at once. Basement temp with no conditioning, after a 95 degree day (and weeks) is 79 (our kitchen was 87 at 6:00pm with no AC).
the photos by the way, are of the southeast, and west exposure.