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

488 points by nitin_flanker 3mo ago

transformerash 3mo ago
[dead]
nialse 3mo ago
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?
- eqvinox 3mo ago
  The heat exchange between that fluid and the ambient air isn't infinitely fast, if it's low enough they can just run "normal" A/C at low power for the humans. They just need to keep the heat in the fluid until it reaches… well… whatever heat dump there is. (cf. top-level post)
- quickthrowman 3mo ago
  > 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.
eqvinox 3mo ago
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?
- maxerickson 3mo ago
  This approach appears to directly reduce energy use (that's what the articles says). The heat would still be going into the local environment, but if there is a reduction in energy use, there should be less of it.
- RicoElectrico 3mo ago
  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.
- amluto 3mo ago
  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.
  - eqvinox 3mo ago
    I was specifically talking about the local microclimate. cf. https://edition.cnn.com/2026/03/30/climate/data-centers-are-having-an-underrported 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.
    - amluto 3mo ago
      Indeed. If the datacenter uses less total power, it produces less waste heat. If you manage to use the waste heat to avoid generating heat somewhere else (that the article calls heat recovery) then there’s a further reduction in total heat output.
qsxfthnkp2322 3mo ago
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?
- jazzyjackson 3mo ago
  Their valuation is based on their software stacks’s ability to displace human labor, this is just them eating their dogfood.
  - qsxfthnkp2322 3mo ago
    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.
    - officeplant 3mo ago
      >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.
- pixel_popping 3mo ago
  I feel that the sad reality is that most blogs in the future will be addressed to AI and not humans, it's gonna be quite rare to read directly something as we will have built-in tools within browser and phone and OS and so-on that always rewrite on-demand based on current expertise, wanted tone and so-on. There is a recent study I believe that demonstrated that AIs digest better articles made by AI, which means that it might be just better to let AI write the articles so others AI have a better accuracy in digesting it (and incorporating it in their training data as well). The same as technical docs for any codebase, humans will not read them anymore, only AIs which then translate it to human on-demand, it's already happening, I've worked recently with many new frameworks/codebases without even opening the doc (not even the Github page) and solely asking the agent to gather info for me about it. PS: The reason I feel it will be this way is that it will allow to legitimatize mass data collection indirectly, instead of doing telemetry on page and software level, we will just send all the content automatically to some inference providers (probably provided for free by Google, MS and so-on)
amluto 3mo ago
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.
- ramon156 3mo ago
  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
  - rokkamokka 3mo ago
    Couldn't imagine living with the ~55dBA noise literally all the time
  - skybrian 3mo ago
    It sounds like with this liquid cooling, they won’t need the fans?
    - michaelt 3mo ago
      Some systems use liquid cooling for the GPU and CPU, but air cooling for the PSU, RAM and SSDs. With that said, by the standards of industrial sites data centres are quiet, low traffic and smell free. An industrial area that can’t build a data centre certainly can’t build a steelworks or oil refinery or leather tannery.
htrp 3mo ago
wasn't this announced at gtc in march?
mchusma 3mo ago
This is also the type of thing that makes space based data centers more viable. I was previously more skeptical on the concept but have come around. I do think ground based centers will have better economics when they can be built though, and this addresses noise and water complaints which are the big 2 regional complaints. It seems like lots of bottlenecks are getting solved quickly, except for maybe memory.
- dgellow 3mo ago
  How does that change the calculus for space datacenters? There is still no reasons or benefits to having them in space. You still have to rely solely on radiative cooling. That doesn’t solve any of the maintenance problems. Space datacenters is a really dumb and unrealistic idea Musk is talking about to hype his companies, it’s not meant to actually be done. Anything in space is more expensive and way harder to do, for a datacenter there is no benefit. We aren’t lacking places where to have them on earth
  - battery_staple_ 3mo ago
    > How does that change the calculus To be precise, heat rejection via radiative cooling scales with the fourth power of the temperature (in K) the radiator operates at, all else constant.
  - asdff 3mo ago
    Starlink is already a space based datacenter. No one is up there maintaining it.
    - wolvoleo 3mo ago
      It's not, it's more like a space based network, the processing and storage is minimal.
      - asdff 3mo ago
        By definition it is compute nodes in space. That is what a router is, a computer. Just a matter of scale. They could be improved to more compute and more storage per node. The framework is already there: treat these as disposable vs having to think about supporting them through maintenance.
t0mpr1c3 3mo ago
with efficient heat exchange you could get the coolant up to mash temperature (65C) and run a combined data center/brewery
m3kw9 3mo ago
This is what PC heat sinks uses. Someone could have thought of that
kayo_20211030 3mo ago
> In favorable climates, NVIDIA’s 45-degree liquid-cooling architecture .... What's a favorable climate, apart from, obviously, Greenland? The piece is a little light on details on the correlation between outside temperatures and efficiency & cost. It'd be nice to see even a broad-strokes discussion of that.
- notrealyme123 3mo ago
  The university where i studied uses high temperature cooling since a few years. The weather on Germany ranges to quite high temperatures, but according to the tech stuff they only need active (as in AC) cooling for the higher end of the 30 degrees. The technology is quite fascinating. https://www.kit.edu/kit/english/pi_2024_038_kit-supercomputer-one-of-the-worlds-most-energy-efficient.php https://www.kit.edu/kit/english/pi_2024_038_kit-supercompute...
  - kayo_20211030 3mo ago
    I lived in Munich many years ago, but if the temperature ever went to the high thirties for more than a day we'd expect the end of the world :-)
    - mattmanser 3mo ago
      Speaking from a UK perspective global warming is now noticeable, hot days are hotter and there's more likely to be a heat wave, and that's changed in the last decade. I assume Germany is the same, many years ago really is different to today.
      - kayo_20211030 3mo ago
        For sure. Everywhere. Even observationally, we just all know it's hotter, or wetter, or colder - it's all way more extreme in all dimensions.
        imtringued 3mo ago
uberex 3mo ago
Weird I was daydreaming about why isn't this done the other day (in the context of desert datacentres running on solar anf battery). Glad to see it is a thing.
metabagel 3mo ago
The NASA Ames Research Center Modular Supercomputing Facility is highly efficient, both in terms of electricity and water use. The facility isn't air conditioned. The chips are water cooled, and the inlet water temperature is pretty high I believe - I think it's 90 degrees Fahrenheit. https://www.nasa.gov/centers-and-facilities/ames/doing-more-with-less-nasas-most-powerful-supercomputer/ https://www.nasa.gov/centers-and-facilities/ames/doing-more-... https://www.nas.nasa.gov/assets/nas/pdf/ModularSupercomputing_20220617.pdf https://www.nas.nasa.gov/assets/nas/pdf/ModularSupercomputin...
- rswail 3mo ago
  For those of us that use metric/SI units, 90F is 32.22C/305.37K. Don't the US Military and NASA use metric now?
VorpalWay 3mo ago
I never looked into this, but why would a datacenter consume water for cooling in the first place? Sure, they use some. But just like you fill up the cooling loop in a car, once it is there it just circulates between the heat source and radiators and/or heat exchangers, with perhaps some minimal top off needed (since flexible tubing isn't 100% water proof). Or are they for some unfathomable reason using evaporative cooling in data centers?
- 1e1a 3mo ago
  Yes, they are using evaporative cooling.
  - bozhark 3mo ago
    But you can do that in a closed system and recapture the water
    - quickthrowman 3mo ago
      You cannot have evaporative cooling without evaporating some water into the atmosphere. A closed circuit cooling tower still has water spraying onto the closed loop process water heat exchanger coil and mixing with atmospheric air to evaporate and cool the process water indirectly instead of evaporating and recirculating the process water that doesn’t evaporate directly like in an open-loop cooling tower. I suppose you could condense the evaporated water somehow by using a chilled umbrella or some other ridiculous contraption above the cooling tower, but why would you do that? FWIW I sell and run commercial electrical work, primarily to mechanical contractors who are installing boilers, chillers, cooling towers, and pumps. I spend my professional life immersed in this type of equipment.
      - rswail 3mo ago
        > I suppose you could condense the evaporated water somehow by using a chilled umbrella or some other ridiculous contraption above the cooling tower, but why would you do that? Specifically to reduce the ongoing demand for water. DCs need to get to net-zero on their energy requirements and their water consumption. They are already losing their political license to operate because they're not. That's independent of the noise and other impositions on the local communities. For a DC to be politically acceptable it must be: * Net zero emissions on energy consumption, preferably powered by renewables in addition to the existing local supply. * Net zero on water consumption, especially fresh/drinking water from local supplies. * Low to no noise or other pollution.
why_at 3mo ago
Maybe I'm being dumb, but I don't understand what the innovation is here. I get that they're using liquid coolant at higher than usual temperatures, but why couldn't they do that before? Most of the comparison in the article is for air cooled datacenters but what about other liquid cooled ones? Surely in all the previous datacenters that have been designed there has been someone doing the math and determining what temperature things need to run at, how much energy it will use, how much heat it all will produce, etc. edit: just saw this: >Previous liquid-cooled servers were hybrid: GPUs and CPUs got cold plates, but the rest of the system stayed air-cooled, with finned heat sinks designed to shed heat into moving air. In a fully liquid-cooled server, the cooling for these components needed to be completely redesigned to use liquid.
- loeg 3mo ago
  You have to design your hardware to tolerate being run in consistently hotter conditions. There's a tradeoff between cooling cost and failure rate / capex.
  - AlotOfReading 3mo ago
    Nvidia's automotive and aerospace variants get ratings up to 85C, for comparison.
    - taneq 3mo ago
      Don’t their consumer GPUs run at 85C core temp? Maybe not for as long though.
      - NekkoDroid 3mo ago
        AMD CPUs basically all boost up to 90°C as a relatively normal operating temperature as long as the power (and some other factors) allow it to. I assume AMDs and NVs GPUs do to, but I play mostly CPU bound games so I see mine just sitting at ~60°C under load.
      - frollogaston 3mo ago
sabareesh 3mo ago
I am pretty much doing the same but running the coolant at 40 deg C instead of 45 as my pumps are rated for 45 C max temp. Here is bit more about my setup https://sabareesh.com/posts/blackwell-waterblock/ https://sabareesh.com/posts/blackwell-waterblock/
emsign 3mo ago
Greenwashing, that's all. This is not going to be the standard it's just a light house project to calm some nerves to keep on going.
- briandw 3mo ago
  It's a response to the FUD that is water usage in data centers. Data centers don't use a meaningful amount of water when compared to just about any other industrial application, or many recreational ones. Data centers used about 66 billion liters 2023. source: https://escholarship.org/uc/item/32d6m0d1 https://escholarship.org/uc/item/32d6m0d1 Golf courses used 2 trillion liters in 2020. We won't even bring up almond production.
  - emsign 3mo ago
    The issue is though data centers are being built in areas with scarce water resources and they get prioritized. They still use a lot of water.
    - falcor84 3mo ago
      But that should be handled by local authorities raising water prices to account for that - preferably to above the cost it would take them to build up the needed water augmentation - rather than as a worldwide environmental concern.
    - briandw 3mo ago
      Maybe. I see the real issue as being that people are scared by change and politicians are taking advantage of the opportunity to get more power.
dialogbox 3mo ago
>Previous liquid-cooled servers were hybrid: GPUs and CPUs got cold plates, but the rest of the system stayed air-cooled, with finned heat sinks designed to shed heat into moving air. In a fully liquid-cooled server, the cooling for these components needed to be completely redesigned to use liquid. Does that mean the whole server board is running in liquid? If true, how do they do maintenance? Replacing parts must be extremely difficult.
- pwg 3mo ago
  The article implied (but did not seem to ever state) that they simply added liquid cooled cold plates to all the other components that were previously air cooled. But it did not sound like they were describing a Cray 2 style liquid immersion cooling system.
prng2021 3mo ago
“That unlocks something beyond energy savings: the possibility of eliminating water consumption entirely.” They’ve made this claim numerous times in the article and I really don’t understand it. The building has tons of water being recirculated through it. That water came from somewhere in the surrounding natural world. How is that 0 water consumption?
- vkou 3mo ago
  After filling the tanks once, subsequent draw would be zero. Most data centers currently use evaporative cooling - where they pull tons of water in, and then... Let it evaporate. Imagine a residential building that reclaims and reprocesses and purifies 100% of all the water it uses. This would be dramatically more difficult and better than the status quo, and would be called 'net zero' by any sensible accounting method. --- Obviously, evaporative cooling is net-zero water use when accounted across the entire globe (the water falls as rain, somewhere, eventually), but it is net-negative for a local community.
- dgacmu 3mo ago
  As someone else noted - it's effectively zero compared to the water evaporated in evaporative chillers. But it's still misleading. The major source of water use in datacenters, by _far_, is the water used in power generation. This improves PUE, which reduces power draw, but the savings are almost certainly under about 20% given that many modern datacenters already operate at a PUE of under 1.2. So if you're running on coal or gas, you're still consuming quite a bit of water indirectly. Now that said again - the water consumption part of this equation is generally overhyped. The power draw is the problem, as are the really bad temporary hacks to the power problem (e.g., what x.ai is doing with "temporary" gas turbines).
  - tylerjharden 3mo ago
    Can you explain what PUE stands for? I am lost.
    - dgacmu 3mo ago
fwipsy 3mo ago
My understanding is that datacenter water consumption is not really that big of a deal compared to other industries, and it's mostly inflated by people who are looking for a reason to criticize AI/datacenters. If Nvidia is hoping to placate those people, I predict it will not work.
- tylerjharden 3mo ago
  I wish there was more transparency and discussion brought to the water and power consumption of other major industries today, as well as the historical use and environmental impact of pre-EPA industries and early manufacturing. I want to believe that relatively, AI data centers and hyperscalers are much less damaging than the industrial revolution-era factories, but without knowing the absolute impacts of both to compare, all this fear mongering and propaganda is going to continue to drive knee-jerk reactions as opposed to well-informed analysis and discussion. Does anyone have any sources for this sort of data?
mv_d5339e31 3mo ago
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sourcegrift 3mo ago
I'm worried about the carbon footprint and other impacts of the higher temperature
mips_avatar 3mo ago
My GPUs at home produce 60°C water. I just wish I had a good use for them.
blondie9x 3mo ago
In a way does this study try to detract from the public backlash against datacenters? Look at the author of the blog. https://blogs.nvidia.com/blog/author/joshparker/ https://blogs.nvidia.com/blog/author/joshparker/ Is this NVIDIA lawyer trying to influence the public perception of datacenter for his company?
Quin_Liu 3mo ago
[flagged]
billjive 3mo ago
“Near” zero?? Leslie Groves, Oppenheimer
vladar107 3mo ago
There's already a city in Finland getting free heating from a Microsoft data center. The problem isn't technical. It's that data centers and district heating grids rarely end up next to each other by accident.
- lrasinen 3mo ago
  Not yet, the Microsoft center is still in planning/construction. But up north there's at least one city (Kajaani) on data center heat; details in another comment.
Toutouxc 3mo ago
If anyone else is disappointed by the terrible AI slop article: It's about a fully liquid cooled data center design. The usual way to cool servers is with air and heatsinks attached to the hot hardware, similar to how your desktop computer or laptop works. As the hardware gets denser and more powerful, you need bigger and bigger heatsinks and cooler air blown over them. At some point you can't make the heatsinks bigger because of space constraints, and you can't blow the air faster (because of noise and efficiency), so you need cooler air. That's when you start running chillers that evaporate water to cool your intake air. This is the huge water consumption that we'd like to avoid. The next step is, obviously, liquid cooling. Again, this is similar to your fancy gaming desktop. You can dump a lot of heat to a liquid medium through a small heat exchanger inside, where you're space constrained, and you can run the liquid through a gigantic heat exchanger outside, despite the temp delta between your coolant and outside air being pretty small. This article is about a system that's FULLY liquid cooled — CPUs, GPUs, memory, networking, the whole thing. That's the actual cool part (pun unintended). On top of that, their solution is optimized to be able to run the coolant quite warm — this obviously limits the heat flux at the hardware side, but it allows you to run the outside heat exchangers "dry", i.e. without wasting any water for its latent heat.
FridgeSeal 3mo ago
> In the right geography — somewhere with reliably cool outdoor air Aaahh, there’s the catch. “Save resources on cooling by building your data centre somewhere cold, and pollute the surrounding environment by dumping your waste heat wholesale into that!” Good job Nvidia, I almost thought we had something good there.
- RealityVoid 3mo ago
  Waste heat from these things is negligible compared to the sun heat. I know people love to hate on these things, but come on...
  - ai_brain_rot 3mo ago
    Well you know, data centers are optional. The sun is not. What a disingenuous comparison, do you hear yourself?
    - mapcars 3mo ago
      Comments on the internet are also optional, yet you do it
      - crypttales 3mo ago
        [dead]
    - balherian 3mo ago
      [flagged]
    - patching-trowel 3mo ago
      Not sure it was a disingenuous comparison. If they’re saying the heat from a DC is drop in the bucket provided by the sun (in a given area), then that heat would indeed be negligible. On the other hand, if that heat comes in water form, and upsets the ecosystem (in a given area), then that would be NOT negligible. Not really about optionality in either case.
eptcyka 3mo ago
What's the reason we can't use heat pumps here to turn that waste heat back into electricity?
- krab 3mo ago
  Too little thermal gradient. What you could do is to use a heat pump to spend a little electricity and turn the waste heat to hot water usable for heating (winter).
Dead_Lemon 3mo ago
Increasing the cooling setpoint of the system isn't exactly a new concept, nor is data centre scale water cooling. Computers can run hot and not throttle. Water is better at moving heat than air. Temperature delta above ambient increase the amount of heat that can be removed, with less mechanical assistance. How exactly is any of this news.
amoshebb 3mo ago
Why only 45? And why water cooling? It strikes me that building everything around room temperature or slightly chilled air is a strange choice. This is already 290K-300K or so, and now this is suggesting that things run fine at 320K or 330K? I've wondered why we couldn't just design everything to operate around 200°C and just use free-cooling by pumping ambient air through. Why don't data centres look more like chicken barns? Do things melt? Are there more errors of some other type at high temperatures?
- joxdosba 3mo ago
  It’d be very hard to make these chips work at 200C, the electrical properties of semiconductors vary significantly with temperature. It would require entirely different chips with entirely different manufacturing processes.
- justsid 3mo ago
  Semiconducting materials have relatively small band gaps, they are insulators that take very little additional energy to become conductors. In contrast good insulators incinerate before they start conducting (or turn into plasma). Energy being energy means that high enough ambient heat can kick electrons into the higher orbitals because the band gap is so small. This also happens at normal ambient temperatures, but those electrons don’t make it very far and there aren’t that many. At 200c a closed gate is not stopping enough electrons from moving through it anymore. At least this is the slightly hand waved technical explanation. Project in Flight on Youtube has an excellent video on how semiconductors work.
randallsquared 3mo ago
It was already near zero compared to various other uses. It's always depressing to me to see a lot of effort put in to "solve a problem" (with subsequent fanfare) which is only a PR or image problem in the first place.
- krupan 3mo ago
  "compared to various other uses" You realize how that vague and open ended clause completely undermines any point you are trying to make, right?
  - randallsquared 3mo ago
    I assumed people here mostly already knew that water usage for data centers was trivial compared to lots of uses like alfalfa, non-data-center power generation, etc. My point used that as a foundation, so I agree that if you didn't already know that, it's undermined. It's a quick thing to dig into though, via search or LLM. You could start with Andy Masley: xcancel.com/andymasley / x.com/andymasley
    - pjdesno 3mo ago
      Most people don't plant an alfalfa field in the desert and then try to use the local municipal water supply for irrigation. Some of the folks looking to build datacenters to cash in on the AI craze aren't as bright as that.
      - randallsquared 3mo ago
        Water is pretty fungible, so while it might not be that alfalfa fields in the Arizona and southern California desert are irrigated from a residential pipe, it's the same water either way. Whether the water arrives at the field/datacenter via municipal pipe or irrigation canal doesn't seem relevant, except that a municipal pipe probably could supply most datacenters' needs, while desert alfalfa has a whole different scale of usage. But if your point is that no one would farm alfalfa in the desert and use water that would otherwise be available for residential use, you are quite wrong.
johnsocks 3mo ago
After reading this I don't understand how this is a breakthrough. Looks to be the same closed cooling loop that is already in place in most commercial and industrial cooling applications. The article mentions being able to place a radiator outside in appropriate climates to reject the stored heat in the water/glycol loop. So everywhere thats not in the north pole would still need a condensing loop. Am I missing something?
crypttales 3mo ago
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rglover 3mo ago
Semi-related. I think a better solution to this DC problem (and a nice revenue stream for vendors) is to figure out something like this [1][2] at scale. Basically, instead of saying "we're going to subsidize our DC build outs by increasing your energy costs," say "if we can install a small compute node that receives workloads in your house (make it a kit so it's easy), you get the heat for 'free.'" I'm ignorant to the specifics of how this might work (and whether it'd even be feasible at a cost/logistics level), but it feels far less invasive and far more sustainable as an armchair thought. Curious if anyone has worked on something like this and what sort of gotchas you've found. [1] https://www.heata.co/ https://www.heata.co/ [2] https://thermify.cloud/how-it-works/ https://thermify.cloud/how-it-works/
maerF0x0 3mo ago
> and the same liquid can be recirculated in a closed loop so no new water is consumed to cool the chips That doesn't mean a datacenter doesn't have a very high _initial_ need for water, or to replace _some_ amount of leakage, replacement etc (agreed it will be way lower than say a swamp cooler). For example, they could be using millions of gallons as a sort of "ballast" to keep the water temperature very stable in the short run. This whole projects depends on the whole stack of components to be able to tolerate 45c from memory, drives, the lighting of the building, the humans ...
- interactivecode 3mo ago
  As long as the water that goes in, doesn’t come out. The inital water requirement is fine. What is problematic in most cases is the warm water containing pollutants is just pumped straight into our local waste water systems or rivers.
- frollogaston 3mo ago
  The entire room wouldn't be 45˚C, or even the entire machine, just the liquid-cooled components.
kingofmen 3mo ago
Points for effort, but this will do literal nothing to appease the opposition, since the "water use" thing is a myth anyway. It's probably good, it sounds like it will be more efficient and efficiency saves resources for other uses, but politically it's completely useless.
- jmartrican 3mo ago
  Do you have any references for this comment: '"water use" thing is a myth anyway'. I would like to show my kid who keeps complaining to me about AI water usage.
  - rcpt 3mo ago
    https://blog.andymasley.com/p/the-ai-water-issue-is-fake https://blog.andymasley.com/p/the-ai-water-issue-is-fake
  - superxpro12 3mo ago
    how does this square against georgia just ignoring it draining the water supply, https://www.politico.com/news/2026/05/08/georgia-data-centers-water-00909988 https://www.politico.com/news/2026/05/08/georgia-data-center... and reports of undrinkable water due to the ai center construction? https://www.bbc.com/news/articles/cy8gy7lv448o https://www.bbc.com/news/articles/cy8gy7lv448o even in the article you linked, it admits AI data centers CAN harm water supplies "Individual data centers can sometimes stress local water systems in the way other industries do, but when you use AI, you are not contributing to a significant problem for water management compared to most other things you do in your day to day life. " What is the point youre trying to make? He also posits in the popular NYT article about a data center sucking up all the water: "But the reason their taps ran dry (which the article itself says) was entirely because of sediment buildup in groundwater from construction. It had nothing to do with the data center’s normal operations (it hadn’t begun operating yet, and doesn’t even draw from local groundwater). The residents were wronged by Meta here and deserve compensation, but this is not an example of a data center’s water demand harming a local population." And its like he claims "its not ai data centers themselves, its the construction of them" as if its an important distinction that exempts data centers from harm. It's not. One day, the data center wasnt there, now it is. And the sudden presence of that DC caused the water problems.
pjdesno 3mo ago
Water use isn't a myth. Our data center is mostly air-cooled, with 100F hot aisles and chilled water going to heat exchangers in every third rack position, although some of our newer GPU racks use chilled water directly. For most of the year that means we don't need chillers - the warm water return is sufficiently hotter than outdoor temp that heat "flows downhill" with a bit of pumping. But we use an evaporative cooler to carry that heat away outside, because it's more efficient. If you look up the heat of vaporization of water, that means we evaporate about 10,000 gallons of water per day per megawatt of power dissipated. We're on canal off a large river, and we don't dissipate all that many megawatts, so I believe the water use isn't significant. Using air as the working fluid to draw heat from your machines has a limitation - humans have to breathe that air whenever they work on the equipment, so the temperature is limited. Once the exterior temperature nears your hot aisle air temp, you either need active A/C to create a heat source hotter than ambient, or an evaporative cooler to lower the "effective" ambient temp to the dew point. Liquid cooling lets you run your working fluid a lot hotter without killing folks like me who go into the data center, although honestly 45C sounds like an incremental improvement over the 100F places like ours are already running. (although to be fair, the warm water return from the heat exchangers is no doubt somewhat less than 100F) It also lets you run your "cold" side a lot hotter - if you "chill" your water down to 100F (38C) on a hot day, it's still cold enough to carry away a lot of heat at 45C. (I'm skipping over the fact that there are multiple heat exchanger loops involved - e.g. any system with an evaporative cooler needs a heat exchanger to keep leaves and bird shit outside the building where it belongs)
- j45 3mo ago
  May I ask where this datacenter you're referring to is located? State and country would be super helpful. I disagree if there is an assumption or premise that all datacenters use water for cooling. Datacenters are not built or operated the same, nor have a requirement for water cooling, or evaporative cooling. Water use is partially a myth for sure, because it's not a certainty or requirement in every datacenter, ever. If water is used for evaporative cooling, it's used in places that the cooling can't work above a certain temperature. Say, for example the US where it gets over 120 degrees farenheit. The inability for cooling equipment to perform when it's extremely hot might be supplemented my multiple technologies cooling together, including evaporative cooling. So evaporative cooling might be common in the US or other regions like it. There are many datacenters that don't need to consume water at all for cooling, except for a water cooler to drink from, and sprinkler systems for fire suppression. They are engineered and cooled just fine. The demand for datacenters and money in this space will likely solve the water usage, if for no other reason, than to increase flexibility of locations. If anyone is curious a bit more about how: Datacenters locations optimize 3 main factors.. Power, Cooling, and Fibre. We know the climate of location isn't the same everywhere in the world where datacenters are located. One thing that can get missed among the water hyperventilating crowd is that datacenters are designed for the need of the location's climate, and what it takes to cool. Too many folks spreading the information are usually non-technical, and get their education about datacenters from social media. There are many places in the world, including in Canada, where cooling is built in 6 months of the year to outdoor air. The temperature isn't high enough in the summer to warrant or require evaporative cooling. They can just vent outside, or capture the heat for other purposes. In other areas still, proven building approaches such as countersinking the datacenter for some additional geothermal benefit, local power generation (Solar, Natural gas) and a unique path to the same datacenter is possible. Of course, if foreign companies are wanting to build in a different country, they might by default build how they know for their region and assume it's ok. There is a massive build out of datacenters occurring in Canada right now, they will be built according to how buildings are built in that climate, not importing cooling technology from regions where it's too hot, or evaporative cooling is the only, or most available option. In temperate climates, considerations have to be made for keeping keep buildings warm (not just cool) year round. The nice thing is this is not hypothetical. There is of course, equipment that can have liquid cooling, or we see those fun videos of equipment submerged in liquid operating. These seem to not be the common.
pjdesno 3mo ago
Historically, cooling alone has accounted for up to 40% of a data center’s electricity consumption The key word here is "historically". Modern data centers typically have a PUE lower than 1.2, with the .2 including not only energy spent on cooling but power distribution losses as well.

488 points by nitin_flanker 3mo ago

[dead]

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?

eqvinox 3mo ago
The heat exchange between that fluid and the ambient air isn't infinitely fast, if it's low enough they can just run "normal" A/C at low power for the humans. They just need to keep the heat in the fluid until it reaches… well… whatever heat dump there is. (cf. top-level post)
quickthrowman 3mo ago
> 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.

eqvinox 3mo ago

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?

maxerickson 3mo ago
This approach appears to directly reduce energy use (that's what the articles says). The heat would still be going into the local environment, but if there is a reduction in energy use, there should be less of it.
RicoElectrico 3mo ago
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.
amluto 3mo ago
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.
- eqvinox 3mo ago
  I was specifically talking about the local microclimate. cf. https://edition.cnn.com/2026/03/30/climate/data-centers-are-having-an-underrported 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.
  - amluto 3mo ago
    Indeed. If the datacenter uses less total power, it produces less waste heat. If you manage to use the waste heat to avoid generating heat somewhere else (that the article calls heat recovery) then there’s a further reduction in total heat output.

qsxfthnkp2322 3mo ago

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?

jazzyjackson 3mo ago
Their valuation is based on their software stacks’s ability to displace human labor, this is just them eating their dogfood.
- qsxfthnkp2322 3mo ago
  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.
  - officeplant 3mo ago
    >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.
pixel_popping 3mo ago
I feel that the sad reality is that most blogs in the future will be addressed to AI and not humans, it's gonna be quite rare to read directly something as we will have built-in tools within browser and phone and OS and so-on that always rewrite on-demand based on current expertise, wanted tone and so-on. There is a recent study I believe that demonstrated that AIs digest better articles made by AI, which means that it might be just better to let AI write the articles so others AI have a better accuracy in digesting it (and incorporating it in their training data as well). The same as technical docs for any codebase, humans will not read them anymore, only AIs which then translate it to human on-demand, it's already happening, I've worked recently with many new frameworks/codebases without even opening the doc (not even the Github page) and solely asking the agent to gather info for me about it. PS: The reason I feel it will be this way is that it will allow to legitimatize mass data collection indirectly, instead of doing telemetry on page and software level, we will just send all the content automatically to some inference providers (probably provided for free by Google, MS and so-on)

amluto 3mo ago

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.

ramon156 3mo ago
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
- rokkamokka 3mo ago
  Couldn't imagine living with the ~55dBA noise literally all the time
- skybrian 3mo ago
  It sounds like with this liquid cooling, they won’t need the fans?
  - michaelt 3mo ago
    Some systems use liquid cooling for the GPU and CPU, but air cooling for the PSU, RAM and SSDs. With that said, by the standards of industrial sites data centres are quiet, low traffic and smell free. An industrial area that can’t build a data centre certainly can’t build a steelworks or oil refinery or leather tannery.

htrp 3mo ago

wasn't this announced at gtc in march?

mchusma 3mo ago

This is also the type of thing that makes space based data centers more viable. I was previously more skeptical on the concept but have come around. I do think ground based centers will have better economics when they can be built though, and this addresses noise and water complaints which are the big 2 regional complaints. It seems like lots of bottlenecks are getting solved quickly, except for maybe memory.

dgellow 3mo ago
How does that change the calculus for space datacenters? There is still no reasons or benefits to having them in space. You still have to rely solely on radiative cooling. That doesn’t solve any of the maintenance problems. Space datacenters is a really dumb and unrealistic idea Musk is talking about to hype his companies, it’s not meant to actually be done. Anything in space is more expensive and way harder to do, for a datacenter there is no benefit. We aren’t lacking places where to have them on earth
- battery_staple_ 3mo ago
  > How does that change the calculus To be precise, heat rejection via radiative cooling scales with the fourth power of the temperature (in K) the radiator operates at, all else constant.
- asdff 3mo ago
  Starlink is already a space based datacenter. No one is up there maintaining it.
  - wolvoleo 3mo ago
    It's not, it's more like a space based network, the processing and storage is minimal.
    - asdff 3mo ago
      By definition it is compute nodes in space. That is what a router is, a computer. Just a matter of scale. They could be improved to more compute and more storage per node. The framework is already there: treat these as disposable vs having to think about supporting them through maintenance.

t0mpr1c3 3mo ago

with efficient heat exchange you could get the coolant up to mash temperature (65C) and run a combined data center/brewery

m3kw9 3mo ago

This is what PC heat sinks uses. Someone could have thought of that

kayo_20211030 3mo ago

> In favorable climates, NVIDIA’s 45-degree liquid-cooling architecture .... What's a favorable climate, apart from, obviously, Greenland? The piece is a little light on details on the correlation between outside temperatures and efficiency & cost. It'd be nice to see even a broad-strokes discussion of that.

notrealyme123 3mo ago
The university where i studied uses high temperature cooling since a few years. The weather on Germany ranges to quite high temperatures, but according to the tech stuff they only need active (as in AC) cooling for the higher end of the 30 degrees. The technology is quite fascinating. https://www.kit.edu/kit/english/pi_2024_038_kit-supercomputer-one-of-the-worlds-most-energy-efficient.php https://www.kit.edu/kit/english/pi_2024_038_kit-supercompute...
- kayo_20211030 3mo ago
  I lived in Munich many years ago, but if the temperature ever went to the high thirties for more than a day we'd expect the end of the world :-)
  - mattmanser 3mo ago
    Speaking from a UK perspective global warming is now noticeable, hot days are hotter and there's more likely to be a heat wave, and that's changed in the last decade. I assume Germany is the same, many years ago really is different to today.
    - kayo_20211030 3mo ago
      For sure. Everywhere. Even observationally, we just all know it's hotter, or wetter, or colder - it's all way more extreme in all dimensions.
      - imtringued 3mo ago

uberex 3mo ago

Weird I was daydreaming about why isn't this done the other day (in the context of desert datacentres running on solar anf battery). Glad to see it is a thing.

metabagel 3mo ago

The NASA Ames Research Center Modular Supercomputing Facility is highly efficient, both in terms of electricity and water use. The facility isn't air conditioned. The chips are water cooled, and the inlet water temperature is pretty high I believe - I think it's 90 degrees Fahrenheit. https://www.nasa.gov/centers-and-facilities/ames/doing-more-with-less-nasas-most-powerful-supercomputer/ https://www.nasa.gov/centers-and-facilities/ames/doing-more-... https://www.nas.nasa.gov/assets/nas/pdf/ModularSupercomputing_20220617.pdf https://www.nas.nasa.gov/assets/nas/pdf/ModularSupercomputin...

rswail 3mo ago
For those of us that use metric/SI units, 90F is 32.22C/305.37K. Don't the US Military and NASA use metric now?

VorpalWay 3mo ago

I never looked into this, but why would a datacenter consume water for cooling in the first place? Sure, they use some. But just like you fill up the cooling loop in a car, once it is there it just circulates between the heat source and radiators and/or heat exchangers, with perhaps some minimal top off needed (since flexible tubing isn't 100% water proof). Or are they for some unfathomable reason using evaporative cooling in data centers?

1e1a 3mo ago
Yes, they are using evaporative cooling.
- bozhark 3mo ago
  But you can do that in a closed system and recapture the water
  - quickthrowman 3mo ago
    You cannot have evaporative cooling without evaporating some water into the atmosphere. A closed circuit cooling tower still has water spraying onto the closed loop process water heat exchanger coil and mixing with atmospheric air to evaporate and cool the process water indirectly instead of evaporating and recirculating the process water that doesn’t evaporate directly like in an open-loop cooling tower. I suppose you could condense the evaporated water somehow by using a chilled umbrella or some other ridiculous contraption above the cooling tower, but why would you do that? FWIW I sell and run commercial electrical work, primarily to mechanical contractors who are installing boilers, chillers, cooling towers, and pumps. I spend my professional life immersed in this type of equipment.
    - rswail 3mo ago
      > I suppose you could condense the evaporated water somehow by using a chilled umbrella or some other ridiculous contraption above the cooling tower, but why would you do that? Specifically to reduce the ongoing demand for water. DCs need to get to net-zero on their energy requirements and their water consumption. They are already losing their political license to operate because they're not. That's independent of the noise and other impositions on the local communities. For a DC to be politically acceptable it must be: * Net zero emissions on energy consumption, preferably powered by renewables in addition to the existing local supply. * Net zero on water consumption, especially fresh/drinking water from local supplies. * Low to no noise or other pollution.

why_at 3mo ago

Maybe I'm being dumb, but I don't understand what the innovation is here. I get that they're using liquid coolant at higher than usual temperatures, but why couldn't they do that before? Most of the comparison in the article is for air cooled datacenters but what about other liquid cooled ones? Surely in all the previous datacenters that have been designed there has been someone doing the math and determining what temperature things need to run at, how much energy it will use, how much heat it all will produce, etc. edit: just saw this: >Previous liquid-cooled servers were hybrid: GPUs and CPUs got cold plates, but the rest of the system stayed air-cooled, with finned heat sinks designed to shed heat into moving air. In a fully liquid-cooled server, the cooling for these components needed to be completely redesigned to use liquid.

loeg 3mo ago
You have to design your hardware to tolerate being run in consistently hotter conditions. There's a tradeoff between cooling cost and failure rate / capex.
- AlotOfReading 3mo ago
  Nvidia's automotive and aerospace variants get ratings up to 85C, for comparison.
  - taneq 3mo ago
    Don’t their consumer GPUs run at 85C core temp? Maybe not for as long though.
    - NekkoDroid 3mo ago
      AMD CPUs basically all boost up to 90°C as a relatively normal operating temperature as long as the power (and some other factors) allow it to. I assume AMDs and NVs GPUs do to, but I play mostly CPU bound games so I see mine just sitting at ~60°C under load.
    - frollogaston 3mo ago

sabareesh 3mo ago

I am pretty much doing the same but running the coolant at 40 deg C instead of 45 as my pumps are rated for 45 C max temp. Here is bit more about my setup https://sabareesh.com/posts/blackwell-waterblock/ https://sabareesh.com/posts/blackwell-waterblock/

emsign 3mo ago

Greenwashing, that's all. This is not going to be the standard it's just a light house project to calm some nerves to keep on going.

briandw 3mo ago
It's a response to the FUD that is water usage in data centers. Data centers don't use a meaningful amount of water when compared to just about any other industrial application, or many recreational ones. Data centers used about 66 billion liters 2023. source: https://escholarship.org/uc/item/32d6m0d1 https://escholarship.org/uc/item/32d6m0d1 Golf courses used 2 trillion liters in 2020. We won't even bring up almond production.
- emsign 3mo ago
  The issue is though data centers are being built in areas with scarce water resources and they get prioritized. They still use a lot of water.
  - falcor84 3mo ago
    But that should be handled by local authorities raising water prices to account for that - preferably to above the cost it would take them to build up the needed water augmentation - rather than as a worldwide environmental concern.
  - briandw 3mo ago
    Maybe. I see the real issue as being that people are scared by change and politicians are taking advantage of the opportunity to get more power.

dialogbox 3mo ago

>Previous liquid-cooled servers were hybrid: GPUs and CPUs got cold plates, but the rest of the system stayed air-cooled, with finned heat sinks designed to shed heat into moving air. In a fully liquid-cooled server, the cooling for these components needed to be completely redesigned to use liquid. Does that mean the whole server board is running in liquid? If true, how do they do maintenance? Replacing parts must be extremely difficult.

pwg 3mo ago
The article implied (but did not seem to ever state) that they simply added liquid cooled cold plates to all the other components that were previously air cooled. But it did not sound like they were describing a Cray 2 style liquid immersion cooling system.

prng2021 3mo ago

“That unlocks something beyond energy savings: the possibility of eliminating water consumption entirely.” They’ve made this claim numerous times in the article and I really don’t understand it. The building has tons of water being recirculated through it. That water came from somewhere in the surrounding natural world. How is that 0 water consumption?

vkou 3mo ago
After filling the tanks once, subsequent draw would be zero. Most data centers currently use evaporative cooling - where they pull tons of water in, and then... Let it evaporate. Imagine a residential building that reclaims and reprocesses and purifies 100% of all the water it uses. This would be dramatically more difficult and better than the status quo, and would be called 'net zero' by any sensible accounting method. --- Obviously, evaporative cooling is net-zero water use when accounted across the entire globe (the water falls as rain, somewhere, eventually), but it is net-negative for a local community.
dgacmu 3mo ago
As someone else noted - it's effectively zero compared to the water evaporated in evaporative chillers. But it's still misleading. The major source of water use in datacenters, by _far_, is the water used in power generation. This improves PUE, which reduces power draw, but the savings are almost certainly under about 20% given that many modern datacenters already operate at a PUE of under 1.2. So if you're running on coal or gas, you're still consuming quite a bit of water indirectly. Now that said again - the water consumption part of this equation is generally overhyped. The power draw is the problem, as are the really bad temporary hacks to the power problem (e.g., what x.ai is doing with "temporary" gas turbines).
- tylerjharden 3mo ago
  Can you explain what PUE stands for? I am lost.
  - dgacmu 3mo ago

fwipsy 3mo ago

My understanding is that datacenter water consumption is not really that big of a deal compared to other industries, and it's mostly inflated by people who are looking for a reason to criticize AI/datacenters. If Nvidia is hoping to placate those people, I predict it will not work.

tylerjharden 3mo ago
I wish there was more transparency and discussion brought to the water and power consumption of other major industries today, as well as the historical use and environmental impact of pre-EPA industries and early manufacturing. I want to believe that relatively, AI data centers and hyperscalers are much less damaging than the industrial revolution-era factories, but without knowing the absolute impacts of both to compare, all this fear mongering and propaganda is going to continue to drive knee-jerk reactions as opposed to well-informed analysis and discussion. Does anyone have any sources for this sort of data?

mv_d5339e31 3mo ago

[dead]

sourcegrift 3mo ago

I'm worried about the carbon footprint and other impacts of the higher temperature

mips_avatar 3mo ago

My GPUs at home produce 60°C water. I just wish I had a good use for them.

blondie9x 3mo ago

In a way does this study try to detract from the public backlash against datacenters? Look at the author of the blog. https://blogs.nvidia.com/blog/author/joshparker/ https://blogs.nvidia.com/blog/author/joshparker/ Is this NVIDIA lawyer trying to influence the public perception of datacenter for his company?

Quin_Liu 3mo ago

[flagged]

billjive 3mo ago

“Near” zero?? Leslie Groves, Oppenheimer

vladar107 3mo ago

There's already a city in Finland getting free heating from a Microsoft data center. The problem isn't technical. It's that data centers and district heating grids rarely end up next to each other by accident.

lrasinen 3mo ago
Not yet, the Microsoft center is still in planning/construction. But up north there's at least one city (Kajaani) on data center heat; details in another comment.

Toutouxc 3mo ago

If anyone else is disappointed by the terrible AI slop article: It's about a fully liquid cooled data center design. The usual way to cool servers is with air and heatsinks attached to the hot hardware, similar to how your desktop computer or laptop works. As the hardware gets denser and more powerful, you need bigger and bigger heatsinks and cooler air blown over them. At some point you can't make the heatsinks bigger because of space constraints, and you can't blow the air faster (because of noise and efficiency), so you need cooler air. That's when you start running chillers that evaporate water to cool your intake air. This is the huge water consumption that we'd like to avoid. The next step is, obviously, liquid cooling. Again, this is similar to your fancy gaming desktop. You can dump a lot of heat to a liquid medium through a small heat exchanger inside, where you're space constrained, and you can run the liquid through a gigantic heat exchanger outside, despite the temp delta between your coolant and outside air being pretty small. This article is about a system that's FULLY liquid cooled — CPUs, GPUs, memory, networking, the whole thing. That's the actual cool part (pun unintended). On top of that, their solution is optimized to be able to run the coolant quite warm — this obviously limits the heat flux at the hardware side, but it allows you to run the outside heat exchangers "dry", i.e. without wasting any water for its latent heat.

FridgeSeal 3mo ago

> In the right geography — somewhere with reliably cool outdoor air Aaahh, there’s the catch. “Save resources on cooling by building your data centre somewhere cold, and pollute the surrounding environment by dumping your waste heat wholesale into that!” Good job Nvidia, I almost thought we had something good there.

RealityVoid 3mo ago
Waste heat from these things is negligible compared to the sun heat. I know people love to hate on these things, but come on...
- ai_brain_rot 3mo ago
  Well you know, data centers are optional. The sun is not. What a disingenuous comparison, do you hear yourself?
  - mapcars 3mo ago
    Comments on the internet are also optional, yet you do it
    - crypttales 3mo ago
      [dead]
  - balherian 3mo ago
    [flagged]
  - patching-trowel 3mo ago
    Not sure it was a disingenuous comparison. If they’re saying the heat from a DC is drop in the bucket provided by the sun (in a given area), then that heat would indeed be negligible. On the other hand, if that heat comes in water form, and upsets the ecosystem (in a given area), then that would be NOT negligible. Not really about optionality in either case.

eptcyka 3mo ago

What's the reason we can't use heat pumps here to turn that waste heat back into electricity?

krab 3mo ago
Too little thermal gradient. What you could do is to use a heat pump to spend a little electricity and turn the waste heat to hot water usable for heating (winter).

Dead_Lemon 3mo ago

Increasing the cooling setpoint of the system isn't exactly a new concept, nor is data centre scale water cooling. Computers can run hot and not throttle. Water is better at moving heat than air. Temperature delta above ambient increase the amount of heat that can be removed, with less mechanical assistance. How exactly is any of this news.

amoshebb 3mo ago

Why only 45? And why water cooling? It strikes me that building everything around room temperature or slightly chilled air is a strange choice. This is already 290K-300K or so, and now this is suggesting that things run fine at 320K or 330K? I've wondered why we couldn't just design everything to operate around 200°C and just use free-cooling by pumping ambient air through. Why don't data centres look more like chicken barns? Do things melt? Are there more errors of some other type at high temperatures?

joxdosba 3mo ago
It’d be very hard to make these chips work at 200C, the electrical properties of semiconductors vary significantly with temperature. It would require entirely different chips with entirely different manufacturing processes.
justsid 3mo ago
Semiconducting materials have relatively small band gaps, they are insulators that take very little additional energy to become conductors. In contrast good insulators incinerate before they start conducting (or turn into plasma). Energy being energy means that high enough ambient heat can kick electrons into the higher orbitals because the band gap is so small. This also happens at normal ambient temperatures, but those electrons don’t make it very far and there aren’t that many. At 200c a closed gate is not stopping enough electrons from moving through it anymore. At least this is the slightly hand waved technical explanation. Project in Flight on Youtube has an excellent video on how semiconductors work.

randallsquared 3mo ago

It was already near zero compared to various other uses. It's always depressing to me to see a lot of effort put in to "solve a problem" (with subsequent fanfare) which is only a PR or image problem in the first place.

krupan 3mo ago
"compared to various other uses" You realize how that vague and open ended clause completely undermines any point you are trying to make, right?
- randallsquared 3mo ago
  I assumed people here mostly already knew that water usage for data centers was trivial compared to lots of uses like alfalfa, non-data-center power generation, etc. My point used that as a foundation, so I agree that if you didn't already know that, it's undermined. It's a quick thing to dig into though, via search or LLM. You could start with Andy Masley: xcancel.com/andymasley / x.com/andymasley
  - pjdesno 3mo ago
    Most people don't plant an alfalfa field in the desert and then try to use the local municipal water supply for irrigation. Some of the folks looking to build datacenters to cash in on the AI craze aren't as bright as that.
    - randallsquared 3mo ago
      Water is pretty fungible, so while it might not be that alfalfa fields in the Arizona and southern California desert are irrigated from a residential pipe, it's the same water either way. Whether the water arrives at the field/datacenter via municipal pipe or irrigation canal doesn't seem relevant, except that a municipal pipe probably could supply most datacenters' needs, while desert alfalfa has a whole different scale of usage. But if your point is that no one would farm alfalfa in the desert and use water that would otherwise be available for residential use, you are quite wrong.

johnsocks 3mo ago

After reading this I don't understand how this is a breakthrough. Looks to be the same closed cooling loop that is already in place in most commercial and industrial cooling applications. The article mentions being able to place a radiator outside in appropriate climates to reject the stored heat in the water/glycol loop. So everywhere thats not in the north pole would still need a condensing loop. Am I missing something?

crypttales 3mo ago

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rglover 3mo ago

Semi-related. I think a better solution to this DC problem (and a nice revenue stream for vendors) is to figure out something like this [1][2] at scale. Basically, instead of saying "we're going to subsidize our DC build outs by increasing your energy costs," say "if we can install a small compute node that receives workloads in your house (make it a kit so it's easy), you get the heat for 'free.'" I'm ignorant to the specifics of how this might work (and whether it'd even be feasible at a cost/logistics level), but it feels far less invasive and far more sustainable as an armchair thought. Curious if anyone has worked on something like this and what sort of gotchas you've found. [1] https://www.heata.co/ https://www.heata.co/ [2] https://thermify.cloud/how-it-works/ https://thermify.cloud/how-it-works/

maerF0x0 3mo ago

> and the same liquid can be recirculated in a closed loop so no new water is consumed to cool the chips That doesn't mean a datacenter doesn't have a very high _initial_ need for water, or to replace _some_ amount of leakage, replacement etc (agreed it will be way lower than say a swamp cooler). For example, they could be using millions of gallons as a sort of "ballast" to keep the water temperature very stable in the short run. This whole projects depends on the whole stack of components to be able to tolerate 45c from memory, drives, the lighting of the building, the humans ...

interactivecode 3mo ago
As long as the water that goes in, doesn’t come out. The inital water requirement is fine. What is problematic in most cases is the warm water containing pollutants is just pumped straight into our local waste water systems or rivers.
frollogaston 3mo ago
The entire room wouldn't be 45˚C, or even the entire machine, just the liquid-cooled components.

kingofmen 3mo ago

Points for effort, but this will do literal nothing to appease the opposition, since the "water use" thing is a myth anyway. It's probably good, it sounds like it will be more efficient and efficiency saves resources for other uses, but politically it's completely useless.

jmartrican 3mo ago
Do you have any references for this comment: '"water use" thing is a myth anyway'. I would like to show my kid who keeps complaining to me about AI water usage.
- rcpt 3mo ago
  https://blog.andymasley.com/p/the-ai-water-issue-is-fake https://blog.andymasley.com/p/the-ai-water-issue-is-fake
- superxpro12 3mo ago
  how does this square against georgia just ignoring it draining the water supply, https://www.politico.com/news/2026/05/08/georgia-data-centers-water-00909988 https://www.politico.com/news/2026/05/08/georgia-data-center... and reports of undrinkable water due to the ai center construction? https://www.bbc.com/news/articles/cy8gy7lv448o https://www.bbc.com/news/articles/cy8gy7lv448o even in the article you linked, it admits AI data centers CAN harm water supplies "Individual data centers can sometimes stress local water systems in the way other industries do, but when you use AI, you are not contributing to a significant problem for water management compared to most other things you do in your day to day life. " What is the point youre trying to make? He also posits in the popular NYT article about a data center sucking up all the water: "But the reason their taps ran dry (which the article itself says) was entirely because of sediment buildup in groundwater from construction. It had nothing to do with the data center’s normal operations (it hadn’t begun operating yet, and doesn’t even draw from local groundwater). The residents were wronged by Meta here and deserve compensation, but this is not an example of a data center’s water demand harming a local population." And its like he claims "its not ai data centers themselves, its the construction of them" as if its an important distinction that exempts data centers from harm. It's not. One day, the data center wasnt there, now it is. And the sudden presence of that DC caused the water problems.

pjdesno 3mo ago

Water use isn't a myth. Our data center is mostly air-cooled, with 100F hot aisles and chilled water going to heat exchangers in every third rack position, although some of our newer GPU racks use chilled water directly. For most of the year that means we don't need chillers - the warm water return is sufficiently hotter than outdoor temp that heat "flows downhill" with a bit of pumping. But we use an evaporative cooler to carry that heat away outside, because it's more efficient. If you look up the heat of vaporization of water, that means we evaporate about 10,000 gallons of water per day per megawatt of power dissipated. We're on canal off a large river, and we don't dissipate all that many megawatts, so I believe the water use isn't significant. Using air as the working fluid to draw heat from your machines has a limitation - humans have to breathe that air whenever they work on the equipment, so the temperature is limited. Once the exterior temperature nears your hot aisle air temp, you either need active A/C to create a heat source hotter than ambient, or an evaporative cooler to lower the "effective" ambient temp to the dew point. Liquid cooling lets you run your working fluid a lot hotter without killing folks like me who go into the data center, although honestly 45C sounds like an incremental improvement over the 100F places like ours are already running. (although to be fair, the warm water return from the heat exchangers is no doubt somewhat less than 100F) It also lets you run your "cold" side a lot hotter - if you "chill" your water down to 100F (38C) on a hot day, it's still cold enough to carry away a lot of heat at 45C. (I'm skipping over the fact that there are multiple heat exchanger loops involved - e.g. any system with an evaporative cooler needs a heat exchanger to keep leaves and bird shit outside the building where it belongs)

j45 3mo ago
May I ask where this datacenter you're referring to is located? State and country would be super helpful. I disagree if there is an assumption or premise that all datacenters use water for cooling. Datacenters are not built or operated the same, nor have a requirement for water cooling, or evaporative cooling. Water use is partially a myth for sure, because it's not a certainty or requirement in every datacenter, ever. If water is used for evaporative cooling, it's used in places that the cooling can't work above a certain temperature. Say, for example the US where it gets over 120 degrees farenheit. The inability for cooling equipment to perform when it's extremely hot might be supplemented my multiple technologies cooling together, including evaporative cooling. So evaporative cooling might be common in the US or other regions like it. There are many datacenters that don't need to consume water at all for cooling, except for a water cooler to drink from, and sprinkler systems for fire suppression. They are engineered and cooled just fine. The demand for datacenters and money in this space will likely solve the water usage, if for no other reason, than to increase flexibility of locations. If anyone is curious a bit more about how: Datacenters locations optimize 3 main factors.. Power, Cooling, and Fibre. We know the climate of location isn't the same everywhere in the world where datacenters are located. One thing that can get missed among the water hyperventilating crowd is that datacenters are designed for the need of the location's climate, and what it takes to cool. Too many folks spreading the information are usually non-technical, and get their education about datacenters from social media. There are many places in the world, including in Canada, where cooling is built in 6 months of the year to outdoor air. The temperature isn't high enough in the summer to warrant or require evaporative cooling. They can just vent outside, or capture the heat for other purposes. In other areas still, proven building approaches such as countersinking the datacenter for some additional geothermal benefit, local power generation (Solar, Natural gas) and a unique path to the same datacenter is possible. Of course, if foreign companies are wanting to build in a different country, they might by default build how they know for their region and assume it's ok. There is a massive build out of datacenters occurring in Canada right now, they will be built according to how buildings are built in that climate, not importing cooling technology from regions where it's too hot, or evaporative cooling is the only, or most available option. In temperate climates, considerations have to be made for keeping keep buildings warm (not just cool) year round. The nice thing is this is not hypothetical. There is of course, equipment that can have liquid cooling, or we see those fun videos of equipment submerged in liquid operating. These seem to not be the common.

pjdesno 3mo ago

Historically, cooling alone has accounted for up to 40% of a data center’s electricity consumption The key word here is "historically". Modern data centers typically have a PUE lower than 1.2, with the .2 including not only energy spent on cooling but power distribution losses as well.