I have a 2900 sq ft home with 2 units (up & down). I don't think the upstairs vents are properly placed, the cooling seems very ineffecient. I have a large(approx 20'x18') "bonus" room upstairs, like a family room, that is above my garage. There are only two vents for the entire room. My master bath has two vents, one in the main area and one in a very small commode room. There are also vents in two closets, one being with in six feet of the mater bath making 3 vets within 6 feet. There is no vent at all in the upstairs hallway where the themostat is located. The Bonus room is always hot in summer and cold in winter and the bed rooms are always significantly hotter/colder than the hallway which makes the unit run and run. I know it's hard to discuss without seeing but any suggestions would be appreciated, thanks.