Woke up to this note. Are we in the wrong?

I’m staying at a friend’s apartment for a few days with another friend. Since there’s no central AC and three of us were sleeping in the same room, we left the window AC unit on overnight. It wasn’t blasting or anything—we just wanted to keep the room cool enough to sleep.

This morning, we woke up to this note slipped under the door. No one knocked or said anything in person. I understand noise can be annoying, especially late at night, but we weren’t trying to be inconsiderate—we just didn’t want to be sweating all night in a packed room.

I’m wondering if we were in the wrong here. Is leaving a window AC unit on overnight generally considered disruptive in apartment settings? Or is this something that just comes with shared walls and apartment living?

Would appreciate some perspective.