Owner's Manual pg 12 has this info: "no obstacles within 20" of back of unit." There is a diagram showing an awning just above the unit, but no information about clearance. I installed the unit higher on the wall for inside purposes, so the clearance is only about 6" between the far back of the unit and the awning covering it.
I've been in motels where the AC was on all the time. I don't see any warnings about that and would like to know if it stresses the unit, especially in 100 + degree weather.