Underperforming front A/C?

The ONLY way to verify the AC unit is running to spec, is a Temp corrected AMP draw of the compressor. That is what I would do if you were my customer. You look at the SPEC plate of the AC. On that spec plate will be the AMP draw of the compressor. That amp draw is based on 95 degree ambient temp. You run the AC for a minimum of 15 minutes and then take the amp draw with a digital clamp on meter of the compressor wire. For EACH 10 degrees above 95 ambient you add 1 amp to the draw. For EACH 10 degrees below 95 ambient you subtract 1 amp. So if your AC spec is 12.8 amps for the compressor and it is 85 degrees ambient the compressor amp draw should be about 11.8 amps. This just verifies the unit is running to spec. It does NOT give you clues if the AC system is not installed to spec with the baffles and ductwork sealed correctly. If the unit is running to spec, then you dig deeper to find if there is a problem with distribution of the cold air. You also need to verify the SIZE of each AC unit. They will be either 13.5k BTU, 15k BTU or HC. HC is a model that is slightly lower than 15k BTU but is almost 15k BTU. If you post the Model number and brand of each AC I can give you the BTU size. Doug