This doesn't actually work. https://physics.stackexchange.com/questions/261284/how-does-...

> The hot air flowing from outside through your windows could be compressed making it cool.

Compressing air actually makes it hotter, but that's not what's happening. Forcing air through a smaller space makes it flow faster, which ironically makes it less dense -- and hence colder.

It's the same effect that people claim holds airplanes up. (But doesn't. That's mostly the angle of attack.)

I don't understand this heat engine yet, one it exits the bottles it contracts again, heating up? it cools the window but heats up the air?

Alternatively, you could power an A/C with a micro wind turbine. Both have the same problem: no wind, no cooling. I'm currently in 30ºC and the tree leaves barely move.