I am completly opposed to Air-conditions propagandized as a solution to climate change. What is the wright approach to combating this state of temporary relief except from old-fashioned fans? Don’t get me wrong. They do the job for me. I am reffering to finding a solution for people more with health issues or large facilities that are in need of something more drastic.
I’ve been fascinated by this concept of passive radiative cooling, where you have some material that radiates heat to space in an infrared window where the atmosphere is transparent. Apparently, a sheet of such material can be a fair bit cooler than the ambient temperature without any consumption of energy? It would not necessarily be an alternative to air-conditioning, but it could potentially reduce the energy costs quite a bit, while lowering the heat island effect in urban areas.
There are some interesting applications where a radiative surface that is shielded from radiation coming back the other way can emit radiation to cool itself by a few degrees below ambient temperatures. There’s one paper from a few years ago that describes being able to cool to 5°C below ambient temperature even in direct sunlight with some exotic materials.
Interesting stuff.