Thanks for the pictures. I googled water evaporation and temperature reduction and it seems the cooling does come from the evaporation having to do with energy states, etc. That’s why there is so much surface area on these chillers.
My guess is that there is a significant reduction in water amount after having been through these.
Another thing you might have seen is some of the outdoor places in LV using fine misters spread around the tables, etc. These mists pretty much evaporate completely and cool the surrounding air volume....
The chillers are inside in a mechanical room somewhere. Something like this, almost certainly:
