The reason evaporative coolers are cheap is because they use a fraction of the electricity that chillers do.
And note that the majority of data center water usage is indirect via power generation, so using less water on site but more indirectly by consuming more power is both more expensive and less efficient.
Unfortunately, evaporative coolers are the best way to go, for now.
Evaporative coolers are cheap. It can be done with non-evaporative coolers, but is far more expensive to build.
Not to mention a much higher carbon footprint.
The reason evaporative coolers are cheap is because they use a fraction of the electricity that chillers do.
And note that the majority of data center water usage is indirect via power generation, so using less water on site but more indirectly by consuming more power is both more expensive and less efficient.
Unfortunately, evaporative coolers are the best way to go, for now.