13 years is an incredibly long time for something as fast moving as data center development. I guarantee that a _lot_ has changed. I know AWS in particular has gone through multiple entire revisions of their DC designs, and I recall a talk from some of their engineers saying how AWS actually found it more economical to use less cooling and let their DCs run hotter than they used to.

Here’s a recent article from AWS about using closed-loop systems for their AI data centers: https://www.aboutamazon.com/news/aws/aws-liquid-cooling-data...