I work in school that have classes from 07:00 to 22:00. All the classrooms have at least one AC unit, which can be 48,000 BTUS, 60,000 BTU or both. (And usually of different brands and models).
Every day a person pass in all classrooms (with 4-5 different controls), to turning on all air conditioners that will be used in the classroom.

After classes are over, the teacher has the responsibility to turn off the air conditioning of the room that he used.
However, by the time of night, everyone is too anxious to go and rest for another day, and end up turning off the lamps and air conditioning in a hurry, going away without checking if it turned off. Thus, some of these air conditioners are turned on overnight, wasting energy for nothing.

The school have 3 blocks, 2 only with classroom and 1 only with laboratories (physical, chemical and electronic). Each block have at least 12 classrooms. So, we are talking about ~30 classrooms.