I have a room above the garage as my office. The room is always roughly 2 degrees warmer than the rest of the 2nd floor. However, it is even warmer near the floor since the hot air from the garage below HAS to go somewhere.
I normally keep the upstairs cooling at roughly 76-78 degrees and the bottom floor about the same.
If I were to use a small portable air conditioner in the warmer room where I work, would it be more energy efficient for me to have the house left at 78 but have the portable in the warmer room to keep it cooler?
I am going on the assumption of that using the large Central Air on the 2nd floor at 74 degrees would expend a lot more energy than a portable in the room set at the same lvl.