I was just telling my boys yesterday about my G-GF's house. He lived next door and had a window unit...and that was it. He had it in his smallest bedroom and that was his "summer" room where he slept. He had a room that was for spring and fall...and had one for winter that had no outside windows...so it stayed warmer. No central AC...just one window unit for a bedroom that was about 10x9...and it cooled that thing down ice cold.
He also had a big attic fan and another huge window fan mounted in the window that would blow air out in the kitchen.
We spent most nights outside...watching satellites pass over (granted there were a lot fewer of them then than now...and I would chase lightning bugs.
I miss that old man....and those good times.