This video shows how to make one kind of evaporative cooler. Evaporative coolers can lower the air temperature significantly in drier climates using evaporating of water across a porous surface. They're fairly easy to make with stuff you find in a hardware store and may offer some relief for folks who are facing record heat in places without AC.
Imo there are better designs than this. This guy's channel is great though. I've used it to put together some swamp coolers.
The best one though is the one where there is some porous towel or cardboard sheet behind a box fan with a pump that pours water down the porous sheet or whatever. Blow it directly on you for the most relief
The ultra simple method though is my favorite - get an athletic shirt, soak in water, wring it, blow fan on you. Keeps you cool as shit even when it's over 110 degrees
I think you can make a really, really simple one by putting the end of a towel in a bowl of water, then draping the towel over the fan. The water should wick up the towel, at least for a while.
This works but yeah it dries out very very quickly, where its not really worth it and provides minimal cooling. -oh wait, I understand - you put it in the bowl of water. Yeah that would probably work pretty well
When I lived in a very hot I eventually caved and just bought a large one that took 5 gallons of water, it was like 100 dollars but it lasted like 4 hours before I needed to refill.
This one would probably work very very well https://youtu.be/xDze9f6Jx8Q
He used to have e some video with this design, except instead of the supply water going into an icebox, he had it going out to a separate evaporative cooler outside which cools the water down to like 60 degrees, supplies it to the condenser which blows out lies 60 degree air. And he did it all using a solar panel. Pretty ingenious design, I'm gonna keep looking for it but this was the simple design https://youtu.be/nSA1OGhB-WI
Aha! This is the design https://youtu.be/I6u6yCe8RzI
Specifically, the small fan design seems to be the better one, the box fan isn't as good at the indirect cooling people it doesn't suck all the air through the heat exchanger