Re: Solar chimney
And that's where the perpetual motion schemes fall apart,nothing happens passively contrary to entropy.
"Swamp coolers" are old technology but you need yards and yards of piping or terracotta or whatever your heat exchange material will be on the "swapping" end. And then you need an active pump to haul up the water, and a way to clean the marine life out of the plumbing, or maintain filters to do that, and if the water is salty you'll need cupronickel or something else besides copper or aluminum.
Still, if you're in fresh water, don't have zebra mussels, and do have a power supply, water misting and swamp coolers both work. Might invest in a reflective awning or something simpler first though.