Both of the North Dallas Courtyards I stayed at last week had turned off the hallway A/C.

The lobbies were cool and the rooms were preset to a normal level (72 or so) upon entry.

I just assume it's a "green" initiative of some sort. A little odd but it doesn't bother me. In the past, I've stayed in various hotels that completely turn off the room A/C between guests, thus making the room uninhabitable for an hour or so after check-in. That is supremely annoying, but neither of these CY's did that.