Air Heaters are easy to understand, it’s basically just running electricity through a wire, so that excess energy turns into heat. Heating is easy enough that you can do it in the form of a campfire with primitive tools.
Air Cooling is a lot harder. I can’t think of a single way to just up and cool air without the use of something that’s already cold.
So how does Air Conditioning work?
(If it’s just some specific obscure chemical reaction then I’ll be disappointed)