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45°C cooling design cuts data center water use to near zero

blogs.nvidia.com

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Re: 45°C cooling design cuts data center water use to near zero

#11

Post by RicoElectrico »

eqvinox wrote: post #4

On one hand: great! On the other hand: the heat has to go somewhere . So… where? Datacenters already create a warm microclimate in their vicinity, is that getting even worse?

The temperature is independent of the actual heat flux. Also - a quick search suggests that at best the data center coolers run at COP of little more than 10. The inverse of that is the amount of heat wasted just on cooling. Having a system not relying on heat pumps would only make it better. A back of the envelope calculation based on PC AIOs suggests they would achieve a COP of 20 or more. A scaled up system would be more efficient than that, if not just for wider tubes.

Re: 45°C cooling design cuts data center water use to near zero

#12

Post by amluto »

This opens up an interesting synergy: district heating. 45C is low but not unworkable for a district heating loop, and a data center might be able to make a nice pitch to a community if the data center offers to provide heat to a district heating system for free. This brings the value to the local community of a nearby datacenter up from near zero to potentially a few million dollars per year.

Summer is still an issue, but fun solutions are possible. With the right geology, I think it’s possible to heat an underground volume in the summer and recapture (some of) that heat in the winter. In many, many climates, annual heating costs are far higher than cooling costs, at least if people aren’t stupid with skylights. [0]

[0] As a back-of-the-envelope heuristic, heating or cooling load due to conduction and air exchange is proportional to the difference between indoor and outdoor temperature. Outdoor temperatures of -10F to 30F are not unusual in the winter and are 40-80F away from an indoor temp of 70F. But outdoor temperatures in these climates rarely exceed 95F and are mostly lower in the summer, so that’s 15-25F of cooling. And heat pumps are more efficient at smaller temperature differences.

Radiative heating is an entirely different story.

Re: 45°C cooling design cuts data center water use to near zero

#13

Post by amluto »

eqvinox wrote: post #4

On one hand: great! On the other hand: the heat has to go somewhere . So… where? Datacenters already create a warm microclimate in their vicinity, is that getting even worse?

Actual heating due to human energy use is not really a big deal except perhaps locally. Climate change is caused by changing how much heat the earth retains from the sun. Maybe if we stopped using fossil fuels and used immense amounts of nuclear power, we would care about the waste heat. But solar and wind power largely redirect energy flows.

It’s kind of like how brine from desalination is not a global problem for the oceans at all — all that matters is diluting it enough that it doesn’t poison the local ecosystem.

Re: 45°C cooling design cuts data center water use to near zero

#15

Post by palmotea »

qsxfthnkp2322 wrote: post #6

Claude write good. Nvidia has so much money and they can’t afford to pay a human for a day of their time to write a blog post?

> Claude write good.

> Nvidia has so much money and they can’t afford to pay a human for a day of their time to write a blog post?

The shareholders desperately need that money.

Re: 45°C cooling design cuts data center water use to near zero

#16

Post by quickthrowman »

nialse wrote: post #3

Heat exchange is used instead of refrigerating the coolant. Makes sense. How do they manage the indoor climate for the humans working there though? Eventually everything will be at 45C in the building, will it not?

> Heat exchange is used instead of refrigerating the coolant.

There are some systems that pipe refrigerant around the building, but they’re relatively uncommon (VRF or variable refrigerant flow if you want more details).

Glycol and water is cheaper than refrigerant so there’s usually a chilled water loop that passes thru a heat exchanger that interfaces with a chiller (vapor compression refrigeration) to reject the heat from the chilled water loop.

This eliminates the need for evaporative cooling towers.

Re: 45°C cooling design cuts data center water use to near zero

#17

Post by eqvinox »

amluto wrote: post #13
eqvinox wrote: post #4

On one hand: great! On the other hand: the heat has to go somewhere . So… where? Datacenters already create a warm microclimate in their vicinity, is that getting even worse?

Actual heating due to human energy use is not really a big deal except perhaps locally. Climate change is caused by changing how much heat the earth retains from the sun. Maybe if we stopped using fossil fuels and used immense amounts of nuclear power, we would care about the waste heat. But solar and wind power largely redirect energy flows. It’s kind of like how brine from desalination is not a global problem for t…

I was specifically talking about the local microclimate. cf. https://edition.cnn.com/2026/03/30/climate/data-centers-are-...

It's not clear to me what changes are happening here. The siblings to your post seem to be indicating an overall improvement.

Re: 45°C cooling design cuts data center water use to near zero

#18

Post by ramon156 »

amluto wrote: post #12

This opens up an interesting synergy: district heating. 45C is low but not unworkable for a district heating loop, and a data center might be able to make a nice pitch to a community if the data center offers to provide heat to a district heating system for free. This brings the value to the local community of a nearby datacenter up from near zero to potentially a few million dollars per year. Summer is still an issu…

Do you live near a datacenter? Property value goes down, constant humming.. the way we heat up the earth right now, i don't think you have to worry about heating

Re: 45°C cooling design cuts data center water use to near zero

#19

Post by rokkamokka »

ramon156 wrote: post #18
amluto wrote: post #12

This opens up an interesting synergy: district heating. 45C is low but not unworkable for a district heating loop, and a data center might be able to make a nice pitch to a community if the data center offers to provide heat to a district heating system for free. This brings the value to the local community of a nearby datacenter up from near zero to potentially a few million dollars per year. Summer is still an issu…

Do you live near a datacenter? Property value goes down, constant humming.. the way we heat up the earth right now, i don't think you have to worry about heating

Couldn't imagine living with the ~55dBA noise literally all the time

Re: 45°C cooling design cuts data center water use to near zero

#20

Post by officeplant »

qsxfthnkp2322 wrote: post #8
jazzyjackson wrote: post #7

Earlier quoted context omitted.

Their valuation is based on their software stacks’s ability to displace human labor, this is just them eating their dogfood.

Oh I understand funny money We are all fucked. And it’s sad because Jensen seems like one of the rare good CEOs when I listen to him speak. But even Dario says he doesn’t let Claude actually write his blog.

>And it’s sad because Jensen seems like one of the rare good CEOs when I listen to him speak.

Have we been listening to the same person speak for the last few years? Jensen rarely even sounds sane anymore.

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