I know this question has been asked many times, but my situation is slightly different so I thought I'd ask. I am moving into a 2-story duplex, but the only rooms upstairs is a bedroom, bathroom and walk-in closet. There is no attic. The room upstairs is an "A" frame so it's very tall. My roommate has moved in and says it's very hot up there. There's only 1 a/c unit and the thermostat is on the wall of the staircase so it's reading the upstairs temperature. Downstairs is nice and cool, but upstairs not so much. We are closing some of the vents downstairs to see if that helps. Any other thoughts? Thanks!