[sparker72678]

Swamp coolers are not effective during at least July-September, when the dewpoint regularly rises to 65°F+ for weeks at a time.

Drier than the south still isn't dry enough when it's 117°F with a dewpoint of 65°F. You'll end up with output temps in the high 80s (or higher), and the output air will be extremely wet.

[snovv_crash]

Can't you use heat exchangers to stack the effect of swamp coolers, so each level gets another 30° colder until it's comfortable?

[pkulak]

Once you saturate the air, it’s all done.

[thelastparadise]

Is H2O bad to put in the air just like CO2?

[Filligree]

No, but if the air is saturated with H2O then sweating doesn't work. Swamp coolers are useful up to a point; ideally they bring down the temperature until you don't sweat. If they can't, and saturate the air instead, then they're worse than nothing.