In north FL, I have a room of 500 sq ft, blinds on 4 windows kept closed, 8-ft ceiling. Thru-the-wall 9,000 btu a/c, 6 ft off the floor, almost kept me cool in summer but never quite cool enough. I just got a new 13,200 Kenmore. Cannot get room temp lower than 80 degrees. Even with temp control set at its 60-degree minimum, compressor runs for a while (maybe 15-30 minutes), then stops (perhaps this is normal; I am a/c ignorant).
When compressor is on, air coming out of unit is 64 degrees. When compressor is not running, air coming out of unit is 82 degrees.
On other side of wall in which a/c is installed is the garage. A/C goes thru wall of room, then sits in sleeve which itself sits on ceiling of a closet that opens into the garage. A/C tilted 1/4 inch so that water (theoretically) drains toward hole that has been cut in bottom of sleeve, then down thru tube, into bucket. After one day of a/c running, no water has come thru hole/tube. Above closet door in garage is a 14" x 28" screened opening. Back of a/c is about 25 inches from this opening. I just checked temp at this screened opening with compressor not running: 110 degrees. Temp in garage right now is 84 degrees. Side of a/c so hot you can't touch it.
A black thing called a baffle was supposed to be installed somewhere on back of a/c. It broke; was not installed.
Unit was installed by guys generally handy but with no particular knowledge of a/c installation. They did installation in exchange for old a/c. I guess I should have paid Sears to do install; live and learn.
Will welcome suggestions as to how I can get this room cool enough for comfort. Thanks for your patience in reading about this problem. Ed