Huge disclaimer that I'm not an expert on this, but:
Googling suggests that you're trading off electricity used to cool the data center with electricity used to blow the air over the electronics, and that ~25C is the temperature where the sum of those is minimized:
On Oxide and Friends (a podcast by a startup building servers) they claims their choice to use larger quieter fans reduces the power consumption of the fans from ~20-30% of the power a rack consumes to ~2%. Which might suggest that that ~25C number is actually a result of poor hardware choices for moving air more than anything else.
Googling suggests that you're trading off electricity used to cool the data center with electricity used to blow the air over the electronics, and that ~25C is the temperature where the sum of those is minimized:
https://i.dell.com/sites/content/business/solutions/whitepap...
On Oxide and Friends (a podcast by a startup building servers) they claims their choice to use larger quieter fans reduces the power consumption of the fans from ~20-30% of the power a rack consumes to ~2%. Which might suggest that that ~25C number is actually a result of poor hardware choices for moving air more than anything else.
https://youtu.be/xNLxknaj72g?si=TWdQnHIRq_BsOOXi&t=3301