I’ve wondered about this for a long time. Air-conditioners don’t really make things cooler, I think they just pump the heat elsewhere, ideally, outside. That’s why you can’t have a standalone AC unit sitting in the middle of a room.
This Is How Much Hotter Nights in Phoenix Are Because of A/C – Smithsonian: “According to the new study, led by Arizona State University’s Francisco Salamanca, the heat output from all those buzzing air conditioners was highest during the day. But, compared to the blistering heat from the sun, it didn’t make an appreciable difference.
At night, though, was another story. It can be hard to sleep in the heat, and many people keep the A/C running all night. Waste heat from all those air conditioners caused a noticeable amount of warming outside …”