My good friend Matthias shared with me something. He was house sitting and the home he was in did not have a working central air. Instead, a room air conditioner was used to cool the entire house using a relay method. See below:
Matthias was kind enough give us this detailed diagram.
Notice how the air unit is in the GUEST BEDROOM, so the room that it directly cools is a room that nobody occupies.
Now see how the door to that room is only open a crack, as if to focus the cool air into the hallway fan. That fan pushes the cool air down the to another fan which pushes the air around the larger rooms.
I can't tell if this is genius or madness.