Our A/C unit is in the attic in an unfinished area on the second floor. The A/C thermostat is in the finished area on the other side of the wall from the unit. As expected, the the second floor is generally several degrees warmer than the downstairs and we have the A/C thermostat set at what is for us a comfortable 76 degrees. It appears to be working as expected, but while the upstairs is kept at 76 degrees, the downstairs is generally about 5 degrees colder.
Would a simple solution be to partially close some (all?) of the downstairs A/C vents help to raise the temperature there - I would experiment by gradually making small changes? Or would partially closing the vents in any way hamper the efficient running of the A/C?