I haven't designed for data centers specifically, but in every other cooling application that exists direct liquid exchange is not uncommon.

Many, many cooling systems use direct evaporation. Especially, but not only, in drier environments.

There are maintenance concerns, but the operating and initial capital costs are lower for those systems, so they are attractive on that level.

That company's been talked about for years. Are people still talking about Windows? That POS? That is unbelievable.

With Action Item! He'll know what to do!

Find the youtubers you like and stop paying attention to the algorithmic feed.

(And Google. Duh.)

Weren't they one of the biggest players in that space? Who's left in the premium tier, Samsung and Motorola?

I was primarily responding to the often repeated yet totally false assertion that heat pumps aren't good for cold climate usage or are much more expensive up front. As I noted, neither are true for new construction these days.

Operating cost comparisons vary VERY widely, as you note, but in MOST areas heat pumps are basically cost neutral with natural gas. That isn't true with particularly high electric rates and low natural gas rates.

And if you don't have natural gas, I'd be hard pressed to name any areas that heat pumps won't be significantly cheaper to operate compared to other fossil fuel options you might have.

There are many residential great pump units that can operate well down to deep subzero f temperatures. Backup electric resistance heat for truly extreme events is very cheap.

I've designed many all electric whole house heat pump systems in Maine. It's not necessarily a big upcharge in New construction. It can be harder in retrofit if existing ducting is not adequate, and air to water for hydronic systems is currently still a more significant upcharge.