In case some one is about to buy one:
1) get help to buy one the right size. Too big will cool the airand stop cooling before it dries it- leaving you cold & clammy.
2)Read Consummer Reports or similar – for example, the amount of noise they make varies widely.
3) Also be aware that SOME AC’s can run on a “Shabbos clock”, but others will NOT come back on when the electricity is reconnected. This is not only good for Shabbos; for instance you can set it to come 1/2 an hour before you come home from a sweaty commute from work on a particularly hot day.
4) Installed it should tilt out SLIGHTLY. You don’t want water to run IN to your wall or home, but you don’t want all the water spill out the back either. Water in the case of the AC is GOOD- to be available so the unit can splash it up on the Hot coils outside. That water provides about 75% of the cooling efficiency.