No one likes to be hot. Or cold for that matter. We like to be comfortable. Comfort burns a lot of energy which isn’t great but maybe in the future we won’t need it to achieve the temperatures we want. Recent experiments have revealed a process that can cool and heat with no external power.
This is still a very, very new concept with only small return. At this time, there has only been a two degree difference which is nothing to really write home about but the theory can be used to get up to cooling temperatures of -47 degrees.
But that’s the real kicker, they can only do that if they have the right material. Which . . . hasn’t been invented yet. It’s a super interesting story about where we may be able to go in the future but until then, fans use less energy than air cons everyone.