So we have a fairly large 5th wheel toy hauler. We have two A/C's already, one in the master bedroom and one in the main area. The garage area is ducted but with only two vents. This past weekend was very hot and the garage area warmed up but never cooled down too much. Our kids and dogs sleep back there. So the question is, do I add a third unit or are the portable units worth it? The portable units are roughly half the price of a mounted unit.