I recently installed a 2 1/2 ton Goodman CLQ condenser with the manufactures performance rated 5 ton TXV coil on a 2 stage variable speed furnace. The HVAC-Calc shows a heat load of 28,251 BTUH. The system charge is producing a subcool of 15F at 210 psi. Superheat is only about 9F at the condenser. CFM over the coil is 990. The problem is that the unit runs continuously and still can't get the indoor temp below 73F. The air flow is very limited with insufficient cooling to the second floor bedrooms even after adjusting the duct dampers. I have not installed many TXV systems. Do I need to worry about the superheat being so low? Could the system be overcharged? Once the charge is set, can the CFM be increased to provide additional air flow to a second story? What will that do to the subcooling and superheat numbers? Will the TXV compensate for the increased air flow or will it need to be adjusted? Will that have an adverse affect on efficiency? Any other ideas on how to increase comfort and cooling?