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45°C cooling design cuts data center water use to near zero (blogs.nvidia.com)
kingofmen 56 minutes 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 50 minutes 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.
harry19023 25 minutes ago [-]
The original paper that started this meme said "data centers consume water indirectly through the water used for electricity generation" and then counted water evaporating out of Lake Mead behind the Hoover dam as water use. This made the numbers seem gigantic, people got mad at it on social media, and 1 year later here we are.

https://www.sciencedirect.com/science/article/abs/pii/S09213...

superxpro12 42 minutes ago [-]
how does this square against georgia just ignoring it draining the water supply,

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

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.

harry19023 23 minutes ago [-]
"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."

But this has nothing to do with data centers, it has to do with construction. I think getting every mad at all new construction in general is a very dangerous path to go down.

CarlsJrMints 10 minutes ago [-]
That Politico article is a good example of the kind of misinformation that makes the water consumption concern a myth. https://x.com/AndyMasley/status/2053296197679374365

> What actually happened here was that [...] two water hookups at a data center construction site weren't properly registered or linked to a billable account. When the utility noticed the problem, they sent the data center a retroactive bill for all the water, for $147,474 covering ~29M gallons. The data center paid it.

> Did the data center cause the low water pressure? The article very strongly implies a connection, but doesn't give the reader the right numbers to judge whether this actually happened. To figure this out, we need to know over what time the 30 million gallons was drawn [...] That's about 1% of the county's daily water output. There are a ton of ways a water system like this can experience low water pressure, and a 1% dip just isn't one of them.

> [...] the complaint about low water pressure [which led to discovering the billing problem] was coming from a private well that the data center didn't even draw from

spandrew 22 minutes ago [-]
Yeah but that's not what the discourse around water and AI is. When people speak about water and AI/dc's, they're indicating that water is being "taken" from other uses. As if a AI usage will oneday cause you to turn on your facet and nothing but an auto-tuned cackle comes out. That the well has gone dry. That water is a scarce resource (which, sometimes it is, esp. if you're drawing from an aquifer in the southwest)

A data centre's construction sentiment clogging pipes is fixable; an acute issue. The discourse is that AI causes chronic strain.

But like... the same people will watch 2-3 hours of HD Netflix or post on TikTok right after lodging their complaints on Reddit. The MW/h of AI isn't that big compared to these services. And the carbon sync of digital goods, including data centres, pales in comparison to the supply chain of Blockbuster. Nobody gave af then.

The reason they're cherry picking AI is because we're all sick of seeing tech billionaires thrive when everyone else is pressed by inflation and stagnant job markets.

42 minutes ago [-]
protoster 38 minutes ago [-]
Doesn't matter that's it's a myth, it's salient and has become a layperson talking point. This is an official post on nvidia.com that can be quoted: "The NVIDIA DSX reference design for AI factories has zero water consumption"
CalRobert 45 minutes ago [-]
It always seemed weird - where does the water go, after all? I gather it isn't turned in to H2 and O2. I assume it leaves the data center hotter than when it came in, which seems like the real issue?
sophacles 28 minutes ago [-]
Yeah and it's a myth that fracking makes water undrinkable.

I'll bet anything you'd be the guy that won't drink a glass of the "perfectly safe, completely unaffected" water while making such utterly absurd claims.

FridgeSeal 7 hours 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.

crunchiepooker 4 hours ago [-]
I’d love that heat in the winter. Imagine, free heat! Linus heats his pool with excess cpu heat. It’s all about using things wisely and not panicking. AI and datacenters are here to stay, you can’t fight them, but you can leverage their waste for profit.
mrhottakes 3 hours ago [-]
> AI and datacenters are here to stay, you can’t fight them,

Maybe you can't (or don't want to), but people can absolutely fight data center construction. Your lack of imagination doesn't bind others.

__alexs 1 hours ago [-]
Have you read Don Quixote?
dyauspitr 31 minutes ago [-]
But why? I want cheap tokens. Build a data center on every block (or more realistically in all the empty space we have everywhere).
coldtea 3 hours ago [-]
>AI and datacenters are here to stay, you can’t fight them

Sounds more like a threat than something desired

expedition32 3 hours ago [-]
They were banned in my country through a democratic process.

Ofcourse it is easier when they are all owned by foreign companies lol. If they actually made money and provided jobs (lmao) it might be different.

rafram 2 hours ago [-]
I'm not sure which country that is, but it would have to be on a different planet! No country on Earth has banned data centers.
Saline9515 3 hours ago [-]
Which country? Did they also ban AI use to be coherent?
sebzim4500 2 hours ago [-]
I don't see why it would be incoherent to ban datacenters but not AI use.
boulos 1 hours ago [-]
Yep. Google does this in Finland for the Hamina datacenter: https://blog.google/company-news/inside-google/around-the-gl...
nashashmi 1 hours ago [-]
If you don't fight data centers, data centers won't seek solution oriented ways to lower their footprint. You are really saying that you can't fight data center demand. And that is true, but you can restrain their supply, increase their cost, and optimize on low impact approaches.
collabs 50 minutes ago [-]
> If you don't fight data centers, data centers won't seek solution oriented ways to lower their footprint. You are really saying that you can't fight data center demand. And that is true, but you can restrain their supply, increase their cost, and optimize on low impact approaches.

Not that this is an apples to apples comparison but imagine people saying that about nuclear reactors. Yes, we want them to be as safe as possible and as efficient as possible but that doesn't mean we don't build it. And at the risk of being a NIMBY, AI data centers don't have to be located right next to my house. Unlike regular data centers, these can and should be in the frigid cold. That would probably be for the best anyway. All it needs is redundant fiber network connection, right? Also we should probably require all AI data centers to use renewable energy only. All these are doable but the fight against AI data centers has to be practical and solutions oriented, not fighting it for the sake of fighting it.

sophacles 21 minutes ago [-]
Nuclear and datacenter comparisons aren't the apples to apples type you're so fond of.

Any safety measure that requires the humans to do the right procedures the right way for 10^5 years is not safety.

dyauspitr 30 minutes ago [-]
Then ask for legislation that they have to be powered by solar power+batteries or something
altmanaltman 3 hours ago [-]
"Everyone will be living in the metaverse by 2025, you can't fight it so might as well buy virtual property near Snoop Dogg"

It takes one recesssion and all datacenter spending will get rolled back. Yes technology will not go away, AI has been here for over many decades that doesn't mean the current paradigm will continue always and exactly the same forever into the future. If history shows us anything its that paradigms change

budsniffer952 2 hours ago [-]
These opinions are hilarious.

Yeah man, we have had AI like this forever, nothing to see here! Data center usage going to zero!

Galaxy brain stuff.

Meanwhile, we literally cannot build fast enough, and are nowhere near saturation.

sophacles 15 minutes ago [-]
I wonder why dark fiber was so cheap in the early 2000s when google famously started using it to link their datacenters?

Not to mention that a huge percentage of the fiber laid in the 90s was never used. It was put in the wrong place or turned out to be the wrong type or was just lost when the "the internet is the future and will change everything. it runs over fiber and we'll need so much more than we could ever lay" companies went bust.

DanielHB 5 hours ago [-]
Datacenter waste heat even a problem? I only ever heard of nuclear power plants waste heat being a problem when the cooling water is dumped directly into rivers (instead of the ocean).
newsclues 4 hours ago [-]
Waste heat is a problem for cities, why not a large DC?

https://en.wikipedia.org/wiki/Urban_heat_island

zulban 4 hours ago [-]
Even the largest DC doesn't have anywhere near the waste heat of a city.
imglorp 3 hours ago [-]
One of the larger DCs is 7.65 GW on 8000 acres in Texas. It will radiate around 236.3 W/m^2 (compare vs 1000 W/m^2 solar irradiation). This emission continues 24/7/365, while the sun doesn't. So yes, the UHI is real.

That plus all the gas turbines powering it which release many tons of gasses.

And finally all the infrasound from the DC and its generators have impacts on humans and all creatures for many miles away.

Oh and the water consumption.

post-it 2 hours ago [-]
> One of the larger DCs is 7.65 GW

"is" is doing a lot of work in that sentence. The data centre doesn't exist.

thinkingtoilet 4 hours ago [-]
Yes. The hot water the datacenters dump destroys local ecosystems.
boxed 4 hours ago [-]
Citation?
4 hours ago [-]
coldtea 3 hours ago [-]
Why would a citation be needed?
j16sdiz 3 hours ago [-]
Because we want to understand what impact it is?

Residential house emit heat too, but - most of the time - we don't consider them "destroys local ecosystems".. Maybe they do, but we don't treat them as a boolean thing, we try to understand the impact...

MisterTea 2 hours ago [-]
> Residential house emit heat too

You are missing the context of the ecosystem - the topic is water ways. Homes aren't raising the temperature of local waterways which can wipe out entire fish and other aquatic populations while encouraging growth of oxygen depleting organisms and algae. Instead of a river or stream you have a dead stinking waterway.

freedomben 3 hours ago [-]
Unless I'm misunderstanding, TFA is talking about a closed loop system and uses a coolant mix, so yeah I think a citation is needed.
croes 3 hours ago [-]
I guess parent means the heat has to somewhere, closed system or not.

Some nuclear power plants use rivers and lakes, that’s bad for their ecosystems if it’s too much but this system uses dry coolers so the extra heat should be negligible

__alexs 1 hours ago [-]
It goes to space like all the other heat does otherwise we'd be living on a ball of gently rotating lava.
croes 52 minutes ago [-]
The question is, where does it go before.
DanielHB 3 hours ago [-]
Actually yeah, data centers using evaporative cooling shouldn't be causing more waste heat problems than most types of heavy industry. Heck, I would guess that even if datacenters dumping hot water on rivers it shouldn't have much of an impact unless the river is very small.

Shouldn't spread misinformation when there are plenty of other valid points about datacenters.

coldtea 3 hours ago [-]
>I would guess that even if datacenters dumping hot water on rivers it shouldn't have much of an impact unless the river is very small.

That's the extraordinary claim. That is what should need citation, not the other way around.

dirasieb 3 hours ago [-]
coldtea 3 hours ago [-]
The burden on proof should be on "dumping hot water to a river doesn't damage its ecosystem" rather than the opposite...
croes 3 hours ago [-]
That’s not what they are doing

> capture heat directly at the source and transport it to outdoor dry coolers, essentially large radiator coils positioned outside the building.

The heat goes into the air

petit_robert 2 hours ago [-]
>The heat goes into the air

Can confirm : I'm reading this from France, we're in the 8th day of the meanest heatwave the country has known since records exist, and it's expected to last two more.

SkyBelow 2 hours ago [-]
Never really like this because it feels some arbitrary as to what counts as making a claim. Human language is filled with implications, and those implications are filled with implied claims. Yet burden or proof seems mostly used when someone makes one of those implied claims explicit, say by explicitly rejecting one.

"We should do X."

"X is not possible."

There was an implied claim that X is possible and an explicit claim that X is not possible, but often it feels that in such a scenario, it is the second individual who is deemed having a burden of proof.

This is made all the worse that there is rarely a single implied claim, but more a group of related implied claims that are also weighted. Like some combination of "data centers don't destroy the environment" and "or maybe they do, but only in amounts of destruction that are tolerable compared to human behaviors and worth the outputs gained" and even "they modify the environment, but it doesn't count as destruction, just change". And even worse (yet again), different readers of the conversation will find themselves placing different weights on these different interpretations making it near impossible to agree on what the original claim is. Thus the first person who makes an explicit claim gets all the attention which ignores all the messy implied human communications preceding it.

4 hours ago [-]
vlan0 4 hours ago [-]
That's interesting...I don't think I've seen the data to support this
stonogo 3 hours ago [-]
Probably not an accident; see Kim. Data Center Cooling Water Discharge: Assessing Environmental Transparency and Information Gaps, 32 Hastings Envt'l L.J. 177 (2026)

But the work is out there, for instance Miara et al. Thermal pollution impacts on rivers and power supply in the Mississippi River watershed, Environ. Res. Lett. 13 034033 (2018)

Worthington et al. The effects of a thermal discharge on the macroinvertebrate community of a large British river: implications for climate change. Hydrobiologia 753, 81–95 (2015)

Lukšienė, Sandström, Lounasheimo, and Andersson. The effects of thermal effluent exposure on the gametogenesis of female fish. Journal of Fish Biology, 56: 37-50 (2000)

Penk and Williams. Thermal Effluents from Power Plants Boost Performance of the Invasive Clam Corbicula Fluminea in Ireland's Largest River. Science of The Total Environment, vol. 693 (2019)

jason_s 60 minutes ago [-]
article also says:

"The geography caveat matters. A data center in the Scottish Highlands and one in Phoenix, Arizona, face very different realities. But even in warmer climates, the shift toward 45-degrees-Celsius coolant moves operators significantly closer to that chiller-less ideal — where chillers may turn on just a few days a year when the outside air temperature demands it."

PurpleRamen 2 hours ago [-]
Maybe, that's why they want Greenland so bad. Low temperature, many free spaces, no significant nature and if there is one, not enough citizen who can complain. And if they still need water for cooling, there is probably enough from the melting ice they can use.
rafram 2 hours ago [-]
1. Who is "they"?

2. Alaska has all of those things. (Though there's plenty of "significant nature" in both Greenland and Alaska.)

glitchc 2 hours ago [-]
All the money they save on water cooling will be spent on massive undersea fiber lines to move the data to and from the island.
dopa42365 1 hours ago [-]
Those are fairly cheap, hyperscalers have been building more or less their own cables for many years, they cost practically nothing compared to the data centers themselves.

https://resources.telegeography.com/telegeography-content-pr...

cududa 2 hours ago [-]
Ah yes but you can shunt the costs of that off into a public works/ taxpayer funded infrastructure project
rafram 2 hours ago [-]
The vast, vast majority of submarine cable projects are paid for with private money. I'm only aware of a few in the US that have received any public grants (all connecting relatively unprofitable areas like Hawaii, kind of analogous to the Essential Air Service program).
2 hours ago [-]
goodpoint 2 hours ago [-]
No, datacenters are placed near cities because the biggest concern is workforce.
HappMacDonald 18 minutes ago [-]
How much workforce do you think it takes to run a data center?
4 hours ago [-]
misja111 2 hours ago [-]
I'd say that in cooler countries, warm water could be very useful, e.g. for heating houses.
agentultra 3 hours ago [-]
You can’t beat thermodynamics no matter how hard you try.

This shouldn’t be a surprised to the majority of people.

whazor 2 hours ago [-]
With LLM latencies, you won't notice it much.
bluerooibos 3 hours ago [-]
Can't beat thermodynamics - there's no free lunch there.
SecretDreams 1 hours ago [-]
To be fair to Nvidia, they are not the first person to dump their waste heat to a Tmin environment. There's a reason most power plants are near bodies of water.
FrustratedMonky 3 hours ago [-]
Wouldn't building in the far North be easier than Space? At least better than the desert like Arizona?
RealityVoid 6 hours 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...
crypttales 4 hours ago [-]
[dead]
ai_brain_rot 5 hours ago [-]
Well you know, data centers are optional. The sun is not.

What a disingenuous comparison, do you hear yourself?

mapcars 5 hours ago [-]
Comments on the internet are also optional, yet you do it
crypttales 4 hours ago [-]
[dead]
patching-trowel 3 hours 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.
balherian 5 hours ago [-]
[flagged]
sandworm101 5 hours ago [-]
Trust me. In the depths of a northern winter, nobody will complain about "waste heat". Just ask the manetees that huddle near reactor outflows in florida.
ceejayoz 4 hours ago [-]
rytis 4 hours ago [-]
But maybe we want northern winters to stay... northern winters?
13 minutes ago [-]
moffkalast 6 hours ago [-]
On an unrelated note, there are so many em dashes in this article I have to wonder if there was any human involved in the process at all. They could've at least signed Nemotron underneath as to not to offend reality.
joxdosba 6 hours ago [-]
Have you stopped for a second to consider the utter mathematical absurdity of what you’re suggesting here?

It is impossible for a datacenter to meaningfully heat more than the air in its immediate vicinity.

NewsaHackO 5 hours ago [-]
It’s anti AI, so people would actually believe the data centers are going to singlehandly melt the icecaps
xphos 4 hours ago [-]
Well I mean not from the waste heat but they have expectations of GigaWatts of new sustained power because they always want to run. The US has on order of 1-2 Tera watts of power capacity so you are talking about .1% of the grid power if a hyperscalar datacenter takes 1 gig of power. I've seen projections of need 50-100 new gigs of capacity. We will see if that actually happens but if it does we are talk 5% increase in grid loading. It sounds small but that is a tremendous about of power.

I mean there are a lot of solutions to making more power or making more efficient chips but to trivialize the impacts of AI as anti Ai propaganda which is how this comment comes of its a bit propaganda minded itself. I think backlash to AI is direct result of strawmaninh Anti AI as having only deranged opinions and anti progress. Where the datacenters are located people suffer because of high velocity don't care about consequences thinking. Every industry has to planing around people or people will do something crazy like burn the centers or try and nationalize data centers. I definitely think that would be stupid but don't underestimate stupid

tehjoker 3 hours ago [-]
nothing wrong with nationalizing
abc123abc123 4 hours ago [-]
Silence! Do not let fact and reason stop the woke or anti-AI agenda! Only emotions count in this space!
greenpizza13 3 hours ago [-]
Woke != anti-ai. Separate ideas. I’m pro AI and would be considered woke, which I would not use pejoratively.
sidibe 5 hours ago [-]
This has also one of the arguments against AC in France, shame on you for wanting to moving the hot air from inside to outside.
joxdosba 5 hours ago [-]
It’s pretty incredible, especially given that the free education in France is actually rather decent.
prmoustache 4 hours ago [-]
A few AC is one thing.

Many AC in a limited space covered in concrete with almost zero tree in the area is another thing.

We need to be more specific about what we are talking about.

Anyway ACs are not enough in a city. ideally you also want streets with a significant amount of trees and greenery so that there is significant shade and heat from sunlight doesn't radiate too much from concrete/pavement.

f6v 3 hours ago [-]
Well, you can wait for greenery to be planted and grow around houses. It'll take 10-20 years. Or you can wait for your landlord to install the shutters (will never happen). Alternatively, you can get a portable inefficient AC and save yourself from 40 degree heat in a rooftop apartment. The mental toll of sweating 24/7 for months is just too big to theorize about the best way to combat global warming.
joxdosba 4 hours ago [-]
France is not under threat from this.
B1FF_PSUVM 2 hours ago [-]
They're also missing the winter bit, where an AC heatpump needs three ou four times less energy than a resistive heater ... oh well.
amluto 1 days 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.

lrasinen 23 hours ago [-]
Microsoft's already building data centers hooked up to district heating (Espoo and Kirkkonummi, Finland). Heatpumps are amazing.

(Seasonal heat storage is also a thing, Espoo's neighbours have tens of GWh of storage, with a new 90 GWh cavern in the works. Not sure if the systems are interlinked.)

hiAndrewQuinn 11 hours ago [-]
Don't forget XTX Markets in Kajaani! At least last I heard. Free heating for an entire city in exchange for being allowed to build out a data center is a pretty good deal.
lrasinen 9 hours ago [-]
Nice!

Apparently the local supercomputer cluster in Kajaani has also been hooked up in 2021 and is responsible for a fifth of heating.

helsinkiandrew 5 hours ago [-]
In Finland the datacentre heat is boosted to 60–90°C for district heating (new builds tend to use heat pumps) [1]

A 75-MW data center in Mäntsälä has provided 2/3 of the heat for the town (2,500 homes) for a decade [2]

1. https://www.creatingsustainablecities.org.uk/post/case-study...

2. https://www.sustainabilitymenews.com/waste-management/how-fi...

spockz 9 hours ago [-]
In the Netherlands we are already transporting “waste energy” in the form of heat to greenhouses to warm them in winter.

Also interesting that the article states that this engineering problem hadn’t been solved before. Google pioneered running chips hotter than before. Moreover, we have had water cooling in consumer setups for ages. (At least 30 years.) So what is new is that all chips have been attached to the loop. I couldn’t find what they did with PSU though.

ACCount37 7 hours ago [-]
High end server PSUs also have liquid cooling now. I'm not quite sure of what temp ranges they run in though.
spockz 6 hours ago [-]
Apparently SuperMicro also has an existing solution. They are stating very similar numbers: https://www.supermicro.com/en/solutions/liquid-cooling
whateverboat 7 hours ago [-]
I think Nvidia are being a little disingenuous here. If I understand correctly, Bull/Eviden has already solved this problem and is in production in JUPITER.
kergonath 6 hours ago [-]
If I am not mistaken, Bull's warm water cooling requires water at ~30°C, so 45°C is still an improvement.
uberex 18 hours ago [-]
45 is the cool temp so they could send the community a higher temp water to their heat exchanger?

Then 45 or below is sent back on the return.

matt-p 18 hours ago [-]
Yes, but the heat will still likely need boosting by about a further 10 degrees either at the source or end user.

DC inlet is 45°C, outlet is 55°C assuming a 10°C ΔT. By the time that's travelled 500m–1km through pipework you've lost a few degrees, so you're arriving at the HIU at maybe 50–52°C. The home radiator circuit then takes that down by around say 12°C, returning ~38°C. Factor in pipe losses on the return leg and you're back at the data centre with maybe 35°C inlet rather than 45°C — meaning the DC output is now only 45°C rather than 55°C, and the whole system gradually degrades each cycle. You could address this by mixing some hot output back into the return to keep the DC inlet stable at 45°C, but eh.

KaiserPro 6 hours ago [-]
> By the time that's travelled 500m–1km through pipework you've lost a few degrees

you'd be surprised. If you have high flow, and the pipes are insulated and underground, then after about a week the temperature drop isn't that much. You do have heat losses, but if you have a high enough continuos flow and a big enough pipe, then it'll be low enough to not worry about, especially if the aim is heat shedding rather than efficiency.

My old flat was powered by both the 1970s boilers across the way, and more recently the massive south london incinerator. The pipe cross section was I think 40cm and at peak carried ~3-5 Megawatts of heat. I think it operated at 150c, but that could be me misremembering (this is the later version of the network: https://www.burohappold.com/projects/veolia-southwark-2-0-he... for the councils is they get a maintained heater network, which is much cheaper than doing it themselves (even more now with gas being so expensive) the power station gets to charge for a waste product and it doubles their on paper efficiency, its a win win.)

matt-p 6 hours ago [-]
Yeah, I mean it does depend on the pipework and season/geography for sure. I was simplifying a bit in that a part of the 'distribution' losses are in the plate heat exchanger as you convert from the "IT" loop to the "district heating" loop. The numbers are roughly right, potentially slightly worse in deep winter when it matters the most.
superluserdo 17 hours ago [-]
>Factor in pipe losses on the return leg and you're back at the data centre with maybe 35°C inlet rather than 45°C

Surely having the input fluid being colder is a benefit, not a problem? Just run the fluid more slowly through the system?

matt-p 14 hours ago [-]
In essence you can't really because slower flow rate makes the heat transfer less efficient. You'd be halfing the flow rate in that example.
gooseh 8 hours ago [-]
But a larger delta-T makes it more efficient?
matt-p 6 hours ago [-]
[dead]
dist-epoch 8 hours ago [-]
Maybe you can use a heat exchanger, like in nuclear power plants, and separate the data center flow from the outside flow, so they can go at different speeds.
matt-p 6 hours ago [-]
You would use a heat exchanger normally anyway. Forcing the outside (DH) to be slow would get you that, but there is cost in having low flow in that HXs are less efficient at the far end and you can transfer less heat in the same pipework (it would more than half the district heating capacity). So in practice, not really.
abc123abc123 4 hours ago [-]
Already done and in use in the nordics. Most likely in most dc:s in the northern hemisphere with cold winters.
shagie 17 hours ago [-]
Of old... https://web.archive.org/web/20210115152829/https://www.nrel....

It's got a "heat energy to/from campus" exchange in there.

That's a link in March and the air temperature was 31°F.

https://web.archive.org/web/20210708150410/https://www.nrel.... is later with air temperature of 68°F.

w4der 7 hours ago [-]
The diagram you shared has an open loop chiller, are those still needed as a backup?
guyomes 9 hours ago [-]
The data centers can also be used to heat swimming pools [1].

[1]: https://www.bbc.com/news/technology-64939558

annagio_ 5 hours ago [-]
Can we also make a jaccuzi? with bubbles? that would be funny.
SkyPuncher 13 hours ago [-]
Heat pumps can effectively bring that temp up higher.

The problem is really how much energy is actually available.

badpun 22 hours ago [-]
European cities are doing it already.
marcus_holmes 9 hours ago [-]
Blew my mind living in a Berlin apartment, that the heating & hot water was managed centrally for the entire block (not the apartment block, the whole city block). Too used to Anglo cities where everyone does for themselves.
arethuza 1 hours ago [-]
There are about 17,000 heat networks in the UK: https://energysavingtrust.org.uk/business/consultancy-and-st...

Only about 2% of the total heating used though...

DanielHB 4 hours ago [-]
Blew my mind in stockholm that they have hot water at all. In my home country we just have electric heaters at the shower tap.

(seriously though, I knew they had hot water, it just never occurred to me how awesome it is to have hot water on the tap)

adastra22 6 hours ago [-]
New York has central steam heating.
PunchyHamster 8 hours ago [-]
It makes a lot of sense when there is waste heat. But in places where there isn't, having per house or per apartment block heating unit is preferable because you cut on transmission losses and infrastructure cost
marcus_holmes 5 hours ago [-]
As I understand it, it's about economies of scale. It's cheaper to heat enough for the whole block in one big unit than it is to have a couple dozen smaller unit doing their own heating. I haven't really studied it. I'm sure the Germans have, efficiency is a whole cultural value with them ;)
kukkamario 4 hours ago [-]
It still makes sense. If heat is produced by a burning something, it is is more efficient to do that in one dedicated place. It makes it easier to pipe exhaust away from apartments and efficiency can be higher.

Also gas pipes to every home isn't a thing in many countries.

Saline9515 2 hours ago [-]
If you burn waste, you have waste heat.
dzhiurgis 8 hours ago [-]
My parents city in eastern Europe just recently switched from burning russian oil to biomass. Even then prices are constantly increasing while converting entire building to heat pump would drop prices by half. However it’s near impossible due to bureaucracy.
brainwad 8 hours ago [-]
Yep, my European apartment has been heated with waste heat from a nearby data centre since 2013: https://eicher-pauli.ch/referenzen/ewz-waermeverbund-binz-zu...
normie3000 10 hours ago [-]
What's the problem with skylights?
MobiusHorizons 10 hours ago [-]
Windows are harder to insulate than walls anyway, but the most important insulation is in the roof because heat rises, so skylights would leak even more heat than normal windows already do.
bbor 9 hours ago [-]
Your logic is solid, but their usage kinda implies the opposite (that skylights would make summers worse, not winters). That seems possible given the obvious dynamics of increasing the amount of direct sunlight, but based on a quick Kagi the overall effect is actually good for both summer and winter if used instead of windows rather than in addition to windows:

  Introducing skylights allows the total fenestration area (windows plus skylights) to be reduced from a maximum 20% of floor area to as low as 12% of floor area while achieving the same baseline average daylight factor target of 5%, and reduces annual heating and cooling energy use and costs in all but two of the 108 models with skylights analyzed. In other words, when different combinations of skylights and windows are used to achieve the same target daylight factor, the heating and cooling energy cost savings are almost always greater when equivalent daylight comes from top‐lighting (skylights) rather than side‐lighting (windows).
https://www.energystar.gov/sites/default/files/asset/documen...
normie3000 9 hours ago [-]
Probably less good if you want to enjoy the view horizontally.
BenjiWiebe 3 hours ago [-]
Cameras and screens. /s mostly
LazyGooze 8 hours ago [-]
"fenestration" - I love that word!
sgerenser 5 hours ago [-]
Even better is “defenestration,” a fancy term for throwing someone out of a window.
close04 8 hours ago [-]
A home with smaller windows is harder to sell so almost nobody builds homes with smaller windows just because they put in a skylight. Small windows make rooms feel smaller and claustrophobic. A skylight gives light but not a view, and large windows give houses a modern look, efficiency be damned. If you search for "modern house" all you see is walls of glass.
PunchyHamster 8 hours ago [-]
at low low cost of feeling like in cage.

Like, it's good idea for a warehouse, limited for housing, people want windows

PunchyHamster 8 hours ago [-]
> 45C is low but not unworkable for a district heating loop,

*55C is on the output, read article first pls

Main problem is that it wouldn't work with buildings designed for higher heating temperature so it is limited to new builds. And it is not limited just to replacing heaters, hot water system is also designed to work with higher temperatures so heat exchanger used would have to be significantly larger

Another one is that load is not constant on both sides and not exactly something that can be increased on demand (unless you're fine with burning cycles just to electrically heat, but that's massively inefficient)

mschuster91 7 hours ago [-]
> Main problem is that it wouldn't work with buildings designed for higher heating temperature so it is limited to new builds.

That's no longer the case with modern, multi-stage high temperature heat pumps [1]. These consume more electricity, yes, but still achieve far better efficiency than straight burning fuel or resistive heaters.

[1] https://www.buderus.de/de/waermepumpe/hochtemperatur

PunchyHamster 5 hours ago [-]
I guess technically you could put heat pump at destination but that significantly eats into "free heat" part
kukkamario 4 hours ago [-]
And that is why existing installations put the heat pump to production side and then just pipe the high temperature water to district heating network.
ramon156 1 days 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
annzabelle 14 hours ago [-]
I grew up in Northern Virginia, (of AWS US-East-1, MAE-East, and Equinix fame), where there are more data centers than anywhere else in the world, and I never heard organized opposition to them until the last couple of years. They were mainly viewed as a way for Loudoun County to build their industrial tax base without the downsides of having industrial workers, and allowed them to consistently lower property taxes while having excellent schools. Data centers are unsightly and use electricity and water, but so does literally any kind of industrial facility. They are also pretty quiet, if you exclude the ones using on site gas turbines for electricity.

Property values have consistently gone up in that region for decades, and are up to $6 million an acre if there's enough contiguous land to put another data center on.

Many of the people complaining about datacenters would also complain about literally any kind of development.

amiga386 11 hours ago [-]
You got good data centres, and their construction and operation were likely regulated.

The problem is that apparently you can just ignore that by building in poor places that won't hold you accountable and perhaps don't even have the regulations. If they do, just don't comply with them. Then your gas turbines can be as loud as you like, nobody will stop you. There's this one weird trick where you can pretend your generators aren't turned on, but they are, and they pollute badly. Nobody will call you out on it.

https://www.youtube.com/watch?v=3VJT2JeDCyw

Also you can take people's drinking water to cool your data centre, and promise a water recycling plant, and then just not build it.

https://www.politico.com/news/2026/05/05/xai-water-reuse-pro...

What I forgot to mention is this one weird trick only works if you're a turbo-bastard with an enormous bank account, and the government of the poor place thinks it's in line for a payday.

senordevnyc 50 minutes ago [-]
Well yeah, if you vote to have fucktards run your state or county, you’re going to live under fucktard conditions.
majormajor 13 hours ago [-]
The new gen of AI-boom-construction datacenters seem to be substantially different than the ones I used to go when working at companies whose software ran inside them. Those were running air-cooled rack servers, which is a whole different world from these things. The couple of the new gen I've seen have been much larger and much more turbine-happy.
lbriner 5 hours ago [-]
The US is very different from Europe. You have enormous amounts of space so even a Data Center that is "close by" is probably still a mile or more. In smaller places like European countries, the data centre wall might only be 100 yards or less from the back of your house so the proximity blocks light and makes you feel encroached on, even if no-one is peeping. In lots of cases, the center might have been built on open land so it is not surprising people don't appreciate their view changing from open land to "very large and tall building"
square_usual 1 hours ago [-]
No? I live very close to Loudoun county, there's DCs across the road from homes.
juneyi 12 hours ago [-]
i'm confused on the humming part, i've driven by them many times and they're just...large, sorta ugly, buildings. but that's really it. i wonder if i walked up to a building i'd hear the humming. quite surprised to learn that they emit a humming that bothers nearby folks
al_borland 12 hours ago [-]
I haven’t been in an AI data center, but have been in several others, and worked in a smaller one. I never really hear anything until I open the door to a computer room… and I’m one of those people who is bothered by the electrical noise in my walls.
audunw 12 hours ago [-]
Maybe those complaints are for datacenters using gas turbines for power. I think some of the recent ones (xAIs?) was built without sufficient power from the grid.
mukbangpervert 9 hours ago [-]
xAI colossus was built without sufficient grid power, so uses "mobile" gas turbines to generate power.

It's absurd, and serves as evidence that we need a confiscatory wealth tax, if we want to maintain a society.

inglor_cz 6 hours ago [-]
For me, it is evidence that our ability to build new power stations has seriously eroded, mostly due to bureaucracy, and that we need to fix this if we want to maintain competitiveness.

Consider the following graph which shows the power generation capabilities of China vs. the US during the last 40 years.

https://www.notboring.co/p/the-electric-slide?utm_source=sub...

The fact that data centers need to resort to gas turbines is downstream from this bureaucratic, NIMBY-driven impotency.

amluto 22 hours ago [-]
I’ve been to datacenters, but not the huuuge ones people seem to talk about in the context of AI. They are noisy inside (due to air cooling, which is largely avoided by the tech in the OP), but they’re entirely unremarkable outside compared to any other commercial or industrial building. Computers are not inherently loud, nor is power conversion.

Power plants are all over, even in populated areas. They’re not so bad either (except perhaps coal).

There is no fundamental reason that datacenters need to be especially unpleasant to their neighbors.

loeg 17 hours ago [-]
On-site natural gas turbines at a handful of DCs are genuinely loud. In general I agree that DCs are mostly fine neighbors, but maybe louder power plants aren't.
TitaRusell 17 hours ago [-]
Yeah this is it. You can make really nice datacenters that are basically quiet and environmentally perfect. This was never in dispute.

But that is not how corporations roll. They want the cheapest shit that they can get away with. No regulations only corruption. Which is middle of nowhere America.

spongebobstoes 16 hours ago [-]
they just want data centers now. most companies would rather use solar, but they can't on short timelines due to land use regulations (and import tariffs)
CamperBob2 16 hours ago [-]
And if they put them in the middle of nowhere, I don't see why there's a problem.

What I don't understand is putting these things in populated areas.

lstodd 15 hours ago [-]
Would you like to work in the middle of nowhere?
loeg 21 minutes ago [-]
30 minutes outside of the suburbs doesn't sound like an awful commute.
SoftTalker 14 hours ago [-]
After construction, not all that many people work at a data center. Some ops staff, maybe a small security team.
lstodd 38 minutes ago [-]
So let's spit on those 'not so many people' from our ivory tower?

Besides, it's not about people, it's about power. Pulling a few MW into middle of nowhere is prohibitively expensive.

CamperBob2 12 hours ago [-]
If they can be deployed in low-earth orbit with nobody working on them, they can be deployed 20 miles east of Bumfuck, Nebraska with nobody working on them.
cameron_b 3 hours ago [-]
The physical threat model of the Nebraska option does not rely on the tyranny of the rocket to keep intruders away.
vablings 19 hours ago [-]
It's like anything else in this world. Corner cutting and being shitty leads to shitty outcomes
pdoege 12 hours ago [-]
When I was building data enters in populated areas there were regulations for noise, visual signature, power usage, and etc. It looks like a lot of these newer sites are in low regulation areas. Which is great for profit margin, and not so great for neighbors.
senordevnyc 49 minutes ago [-]
Sounds like the “don’t tread on me” crowd is about to find out the value of regulation.
mixdup 19 hours ago [-]
>There is no fundamental reason that datacenters need to be especially unpleasant to their neighbors.

Sure there is, being a good neighbor costs more than being a bad neighbor

wolvoleo 22 hours ago [-]
It depends a lot on things like geology and some people are a lot more sensitive. It is really an issue.

I don't have any datacenters near me but I can hear some heavy hums from the washing machine 3 floors up when it put my head on my pillow, for some reason it just propagates through the building physically. When I walk around I don't hear it. Datacenter noise can be the same.

IMO they should be put away from habitation, there's no reason for them to be near there anyway

amluto 19 hours ago [-]
> I don't have any datacenters near me but I can hear some heavy hums from the washing machine 3 floors up when it put my head on my pillow, for some reason it just propagates through the building physically. When I walk around I don't hear it. Datacenter noise can be the same.

Right. Vibration propagates through solid (and liquid) materials.

But this can all be measured and controlled, and there's nothing special about datacenters. A building that is hundreds of feet away will couple to your pillow much less strongly than a washing machine in your building. And the washing machine often has a wildly unbalanced load and minimal decoupling between itself and the floor, whereas a big fan in a datacenter or other industrial building ought to be balanced and also ought to be installed on decoupling mounts.

If datacenter operators (cough xAI) are being lazy about properly selecting, installing and maintaining equipment, then you can have a problem. Otherwise you have a much smaller problem.

thewebguyd 21 hours ago [-]
> IMO they should be put away from habitation, there's no reason for them to be near there anyway

I agree, but that's a hard problem (in the US anyway). Unless you're plopping data centers in the middle of national parks, or in the middle of the desert where water is going to be a problem, you are nearly always going to be within some small mile radius of civilization. Plus the cost of trenching new fiber out in the middle of nowhere.

The same reasons humans want to concentrate in a particular area (access to jobs, infrastructure) are the same things that data centers need.

Once water-less cooling tech like this improves then yeah, just plopping them in the middle of the unpopulated desert becomes viable (assuming you can get the fiber out there and latency is tolerable), so long as they generate their own power.

dgoldstein0 18 hours ago [-]
The climate requirements to run at this hotter temperature still probably means it'll require more active cooling in the desert during daytime /summers. Assuming we're talking about hotter desert environments like US southwest. That might make your proposal not as economical.

Imo we should just solve the problems with data centers being near cities. Manage/regulate the noise and any waste (heat included, it shouldn't drastically impact the neighbors) and make them pay for any utility capacity/reliability upgrades needed. If this article is right and water usage can be nearly eliminated then it seems like the rest should be solvable? Especially if we can take the extra heat and use it for local power or heating needs.

VorpalWay 18 hours ago [-]
You might (but probably not) be able to do district heating with this, but electricity generation is not going to be efficient. Heat is a very low grade form of energy, and you need a large differential to drive a turbine efficiently.

If you cycle between 45 C and 55 C water temperature (as mentioned by the press release), you are only getting a 10 C delta. That isn't even enough for district heating, probably not even with heat pumps.

Now if you have something like a steel foundry, that have much hotter cooling water, you can absolutely use the heat for district heating, but even then it usually isn't enough for cost effective electricity generation. Even when it is waste heat, as the equipment to handle it still costs money and requires maintenance.

amluto 16 hours ago [-]
> If you cycle between 45 C and 55 C water temperature (as mentioned by the press release), you are only getting a 10 C delta.

You are calculating the wrong delta T. To heat a space, you need your working fluid to be warmer that the space you’re heating by an appropriate amount.

55°C is certainly on the cool side to heat a building, but it’s entirely workable with a high-area, highish-thermal-conductivity system. Here’s an actual chart:

https://www.warmboard.com/wp-content/uploads/2022/04/WaterTe...

You don’t actually want an absurdly warm floor.

Even for buildings that need warmer fluid, water at 45-55°C is a fantastic source for a heat pump.

lrasinen 8 hours ago [-]
55 C might be enough to heat buildings but it's right on the edge where domestic hot water needs to be to kill Legionella. So traditional DH systems need to run hotter.

There low-temp/cold DH systems out there that rely on heatpumps in the buildings to extract the heat. Less losses in the network and you can even use them for cooling, but needs heat pumps everywhere.

In comparison, a traditional heat exhanger is pretty simple technology; just a hunk of metal with a valve.

naasking 17 hours ago [-]
> It depends a lot on things like geology and some people are a lot more sensitive.

People said this about high voltage electric lines and wind turbines. Blind tests proved they were imagining things.

retrochameleon 9 hours ago [-]
Look up Benn Jordan's video on datacenter infrasound. Just because you can't perceive the noise doesn't mean it's not there and it doesn't have an effect on the human body, especially over very long periods of time.
derriz 2 hours ago [-]
I was a regular viewer of Benn Jordan until seeing one of his videos about how Apple sucked because the iPad was incompatible with so many MIDI and DAW controllers. He went through his devices one by one, plugging them into the iPad and then showing that the iPad didn't recognize the device.

I thought it was a joke of some kind and eventually he would give the "reveal" but no, he finished the video without ever considered that USB is a host/device connection - and although USB-C confusingly introduced a symmetric cable, you cannot connect two devices back-to-back (one end has to be a host) and expect anything useful to happen. And that's why Apple sells a "camera" kit to allow an iPad to act as the host to USB devices.

Seeing him use an oscilloscope to diagnose an Ethernet issue in an earlier video had given me the expectation that he was technically knowledgeable and interesting. So it was shocking that he could present conclusions with such a confident and knowledgeable air, having missed such a basic and fundamental fact about USB.

And there was no push back in the comments that I could see at the time - so seemingly half a million viewers would have finished the video feeling they had learnt something.

JimDabell 8 hours ago [-]
arjie 17 hours ago [-]
Do you? I live at 4th and Brannan and there was one just off 3rd and Brannan in San Francisco. It was shut down when hosting.com sold it off but I didn't notice it while walking by then and I don't notice it while walking by now.

My GPUs at Hurricane Electric in Fremont are also completely unnoticeable outside the building. Inside, when I'm working at the cabinets it's obviously deafening. Outside you wouldn't even know. Realistically, the predominant sounds at my home are from the traffic on the Bay Bridge so it's nice when there's congestion because it's quiet.

Honestly, I wish there were more urban datacenters. It's getting quite annoying having to make a 1 hr trek to Fremont every time I want to rack a new server.

toast0 16 hours ago [-]
> Honestly, I wish there were more urban datacenters.

There's a lot of them in high rise buildings... but they come with high rise rent.

arjie 14 hours ago [-]
Imagine if one of the amenities in a high-end residential building could be a cabinet haha! That would be amazing. Doesn't make economic sense, but I'd love it. Would love to explain that to my wife. "I know that one has the pool, but we can rack my servers in this one if we live there".
jrnichols 13 hours ago [-]
Something here about water usage, a small data center, and a swimming pool. Combining the three may either be awesome or tragic!

I like this idea. A small cage in an apartment complex would be a huge selling point.

Or even a La La Land on the corner, urban DC in the back. Winning across the board.

xattt 23 hours ago [-]
Noise is a design choice and could likely be legislated away. Reject heat is different than heating from greenhouse gas effects that are “heating the planet”.

No one bats an eye when an air conditioner runs.

Marsymars 15 hours ago [-]
> No one bats an eye when an air conditioner runs.

I find their noise pretty obnoxious. Out of respect for my neighbours, when I get around to installing one, I'll be getting the absolute quietest model available.

dgellow 23 hours ago [-]
> No one bats an eye when an air conditioner runs.

In the US

xattt 21 minutes ago [-]
Now do heat pumps in the winter.
bethekidyouwant 16 hours ago [-]
Data centres aren’t loud it’s the gas power generating stations next to them that are loud.
rokkamokka 1 days ago [-]
Couldn't imagine living with the ~55dBA noise literally all the time
skybrian 23 hours ago [-]
It sounds like with this liquid cooling, they won’t need the fans?
zie 18 hours ago [-]
They almost certainly need fans on the outside of the building to cool the 55C water back down to 45C. But correct, no fans on the servers themselves or even in the building. Except perhaps for the humans, so they can stand to work inside the building, when needed.
michaelt 18 hours 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.

stubish 17 hours ago [-]
If the outdoor temperature is cool enough (maybe 30C?), you just pipe the liquid outside through a large enough loop or heat exchanger to get it back down to under 45C. Even better if you can put the loop in a lake and dump the heat there (maybe not better from an ecological POV though). The pumps moving all that liquid becomes the noisiest component.
energy123 18 hours ago [-]
The humming are the gas turbines which also damages your health.
SamPatt 15 hours ago [-]
>the way we heat up the earth right now, i don't think you have to worry about heating

Nearly 10x more people die from the cold than from the heat.

"...9.43% of global deaths were attributable to non-optimal temperatures, with 8.52% from cold and 0.91% from heat."

https://www.thelancet.com/journals/lanplh/article/PIIS2542-5...

ryan_lane 15 hours ago [-]
This study doesn't factor in droughts, floods, crop death (and starvation), and other non-direct effects. It also doesn't consider wet-bulb events, because it's looking at average ambient temperatures.

I don't think this is climate change propaganda, but your application of this study by evoking it in a discussion about climate change feels like it.

SamPatt 4 hours ago [-]
Deaths from all natural disasters have dramatically decreased over the last century.

I won't bother sharing the source because you'll find some reason to dismiss it I'm sure.

It's interesting you claim my comment is propaganda when I cite a scientific source and yet have nothing to say about the parent comment which claims we no longer need to worry about heating due to climate change. Which of those comments seems more propagandistic?

abc42 21 hours ago [-]
Coldest month average temperature where I live is around -7C, with peaks of -35C. Climate change is not going to increase that average, more like decrease. Typically, of course, electricity price is the highest during that month too.

I think we are going to need heating.

tucnak 22 hours ago [-]
> the way we heat up the earth right now, i don't think you have to worry about heating

So what, winters would be no more? Snow will disappear, no more ice-men and christmas trees, and subzero conditions in general, too?

reaperducer 17 hours ago [-]
And no more food. Or at least not enough of it to feed very many people.

You do eat, don't you?

SamPatt 4 hours ago [-]
As the earth has warmed over the last century, has food production increased or decreased?

If production increased (dramatically) while temperatures increased in the past, could this trend continue?

joe_mamba 19 hours ago [-]
>Do you live near a datacenter? Property value goes down, constant humming

I don't live next to one but I'd take constant humming over the constant stop/go traffic noise, honking, squeaky brakes, slamming doors and revving engines I now have on my western side of the apartment, thanks to the unemployment office the city opened on my street not too long ago.

So how come constant humming is somehow an illegal nuisance, but we've been expected to put up with the much more annoying urban traffic noise for decades just fine?

My parents apartment have constant humming anyway thanks to the HVAC system on the roof of the nearby supermarket and white/brown noise is far more tolerable and easy to tune out than traffic noises.

drnick1 18 hours ago [-]
> we've been expected to put up with the much more annoying urban traffic noise for decades just fine?

For one, there tends to be little traffic at night when most people want quiet in order to sleep. Driving is also something (nearly) everyone does and benefits directly from, so negative externalities are easier to accept. It is much harder to accept a new source of noise near your home you haven't asked for and don't directly benefit from.

brailsafe 16 hours ago [-]
> Driving is also something (nearly) everyone does and benefits directly from, so negative externalities are easier to accept.

This reads a little too close to driving being an inherently good thing or some sort of objective requirement, but it's only that way in certain urban places because the built environment makes it as arduous as possible to do those things without.

Something that pisses me off about many urban places that don't even otherwise require people to drive, is that many who do use their cars the most often have their neighborhoods protected from the noise they contribute to everywhere else. This whole thing of putting apartments only where there's already the most disgusting car-infested thoroughfares; "sorry, can't have an apartment one street in off the main drag, that's only for bungalows! Don't like it? Get richer. Excuse me while I drive through your bedroom and park for free in front."

joe_mamba 9 hours ago [-]
>s that many who do use their cars the most often have their neighborhoods protected from the noise they contribute to everywhere else.

This, so much this. All the noise producing infrastructure in cities is dumped in the highly dense poor areas, and the rich people living in the quiet suburbs in single family home who need to drive in front of your home, are protected by this externality.

ChoGGi 17 hours ago [-]
I live nearby a road going down a coulee that dickheads love to speed down in warmer weather at night. I'd trade that for a hum any day.
energy123 18 hours ago [-]
More noise categories should be illegal or fined in dense areas, not less
joe_mamba 18 hours ago [-]
Agree, but data centers are no inside dense areas though.
energy123 18 hours ago [-]
They're being built in the US next to people's houses with gas turbines

https://xcancel.com/BrianEntin/status/2067930868191035474?s=...

joe_mamba 9 hours ago [-]
To me that only makes clear that gas turbines are the noise issues, no data centers. Surely there exists data centers that work off the main power grid and don't have a natural gas turbine as their own power source.
b5n 17 hours ago [-]
How dare those nasty, dirty, unemployed live their lives under likely desperate circumstance. They are so much worse than corrupt oligarchs pumping and dumping their way into the greed hall of fame.
eru 9 hours ago [-]
> This brings the value to the local community of a nearby datacenter up from near zero to potentially a few million dollars per year.

You are not wrong, but the whole issue is a bit silly: there should be legal ways for data centres (and other commercial operations) to just send a few million dollars a year to whichever community they need to convince; instead of having to dress it up as free heating.

YokoZar 6 hours ago [-]
That means is called property taxes. Datacenters pay a lot of them, and in Loudon county specifically residential property taxes have fallen as a result.
eru 4 hours ago [-]
You mean they have dropped rates, or you mean that residential property values have fallen, and thus they pay less property taxes?
chii 9 hours ago [-]
the datacenter doesn't have a few million dollars to spare.

The heat is waste heat. If it cannot be recovered as a profitable source of energy, the datacenter won't be able to pay that few million dollars.

eru 4 hours ago [-]
> the datacenter doesn't have a few million dollars to spare.

What makes you think so? Datacentres are already very expensive, and getting permissions quicker (or at all) might be worth a couple million dollars.

> The heat is waste heat. If it cannot be recovered as a profitable source of energy, [...]

Yes, they should make all deals that make sense for both parties, definitely. But it's only viable in some places some of the time.

mschuster91 7 hours ago [-]
Recovery isn't the issue, the issue is that district heating systems are pretty much a rarity across the world for a number of reasons. Recovering waste heat - no matter if from datacenters, industrial processes or eve wastewater/sewage - is trivial, but getting the heat to somewhere it still can have a productive "secondary usage" is a massive and expensive problem.
eru 4 hours ago [-]
Yes. There's eg combined power plants that use waste heat from power plants to heat houses. The problem is that this tends to make the power plants less efficient at electricity generation.

So this waste heat recycling should only be done where and when it makes sense.

(But that's pretty easy: absent any legal requirements, the involved parties have all the right incentives already. It's all internalised between the parties.)

mschuster91 4 hours ago [-]
> The problem is that this tends to make the power plants less efficient at electricity generation.

Huh what? Never heard of that one before.

> absent any legal requirements, the involved parties have all the right incentives already

Well... that's the problem, they don't. Sure, datacenter operators could go and offer to install district heating, waste heat recyclers and whatnot, and it would likely be profitable. But, and here it gets annoying, it's not profitable enough.

verve_rat 9 hours ago [-]
But paying the money is less resource efficient than using the waste heat for a productive use. As a general rule we should probably insensitvise good use of resources that benefit the general population.
eru 4 hours ago [-]
Using waste heat like this only makes sense in some places some of the time.

And when it does, people should obviously go for it. Work out a deal, when there's some surplus to share.

dzhiurgis 8 hours ago [-]
Im general. But the way AI is growing is not a general case, but exponential. It shouldn’t be slowed down by generalisations.
Version467 7 hours ago [-]
Surely there's something missing from your argument. It shouldn't be slowed down because it's growing exponentially?

Presumably you think that the end result of extreme and rapid ai growth is beneficial to most and that is why it shouldn't be slowed down? That arriving earlier at whatever end-point you have in mind will provide so much benefit that it's worth disregarding the pains to get there?

Or is there something else to your argument? Because if there isn't, you are staking an awful lot on your expectation coming true. Especially that going slower doesn't provide any worthwhile benefits to the outcome.

dzhiurgis 4 hours ago [-]
I mean it's kinda obvious you don't wanna throw baby out of bath water when technology is at its infancy.

There's nearly 0 downsides to absolute majority of people to continue building out datacenters. Yet I see this derangement syndrome with headlines like "I’d Rather Risk Cancer Than See AI Move This Fast"[0]. This is just as farcical as calling cars a national security threat in 1920s and any sufficient army should be run by cavalry.

0: https://www.theatlantic.com/technology/2026/06/ai-cancer-pro...

one33seven 10 hours ago [-]
The value of an AI data center in your area is negative, not near zero. Pollution, water use, heat, infrasound (https://www.youtube.com/watch?v=_bP80DEAbuo) and so much more... But at least we may get some cheap heat in the future
JimDabell 8 hours ago [-]
bbor 10 hours ago [-]
Heat is not a cost -- no one is physically cooking because they live within miles of a building with computers in it.

Water usage is not a cost with this new technology -- that is what the article is about.

Infrasound is terrifically understudied and should not be discussed definitively based on the findings of a highly-biased amateur, but regardless: fan sound is not a cost with this new technology -- that is what the article is about.

Re:pollution, I suppose all buildings are kinda inherently polluting just by existing. So you've got them on that point!

Most importantly, actually: the person above clearly knows about all this, and was just discussing the benefits on their own. I love me some pedantry (really!) but this attempt seems counterproductive, sorry.

sysguest 9 hours ago [-]
> Heat is not a cost

hmm? maybe it differs from time to time? on summer, it IS cost (nearby need to run AC)

one33seven 6 hours ago [-]
also ecological and medical problems
why_at 18 hours 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.

RachelF 17 hours ago [-]
The "innovation" is that everything is now attached to a watercooled block.

The rest is marketing: The Cray supercomputer were fluid cooled back in the 1980's, the entire board had an inert liquid flowing across it.

jasonwatkinspdx 14 hours ago [-]
When my grandpa retired from Monsanto chemical back in the 90s, I helped him clean out his office and got a tour of a bunch of stuff.

He showed me their Cray, which had its own dedicated computer room, and they set it up with the coolant pump and fountain unit right in the middle in front of a glass wall facing the hallway so everyone could gawk at it.

indigo945 8 hours ago [-]

    > The Cray supercomputer were fluid cooled back in the 1980's, the entire 
    > board had an inert liquid flowing across it.
You can still do this with any computer, by the way: just submerge the entire board in motor oil. Slightly smelly and might make a mess, but absolutely workable.
alt227 7 hours ago [-]
Mineral oil is the usual substance used, as its clear and non smelling.
geokon 3 hours ago [-]
Are pretty much all surface mounted components fine with this?

I wanted to waterproof a micro devboard by submerging it in mineral oil. I was worried the board may delaminate or components would turn to goop

frollogaston 15 hours ago [-]
The innovation is being able to run the chips at higher temps without ruining them too quickly.
dietr1ch 14 hours ago [-]
Haven't AMD CPUs been targeting a 95°C limit for 5+ years already? I'd have guessed servers could do 60°C without degrading a whole lot before switching to more power efficient hardware is available.
frollogaston 14 hours ago [-]
95˚C is the core temp, not ambient. My parent comment was probably wrong though, see https://news.ycombinator.com/item?id=48667527
maxnevermind 12 hours ago [-]
> everything is now attached to a watercooled block

Does it increases manufacturing and operational cost of such racks?

16 hours ago [-]
fennec-posix 17 hours ago [-]
My partner lamented the same thing... Cray was doing this 40+ years ago
briandw 16 hours ago [-]
Cray used Fluorinert, a chlorofluorocarbon. So not exactly a environmentally friendly solution.
justsid 2 hours ago [-]
That shouldn’t be a problem then given that we don’t care about environmental impacts anymore.
trhway 16 hours ago [-]
Bad quality of water clogging the pipes integrated onto the PCBs (thus requiring to replace the PCBs) was said to be what were killing those few USSR Elbrus supercomputer installations.
toast0 16 hours ago [-]
> 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.

It seemed like a pretty big deal ~ 2011 when big companies were running their (air cooled) datacenters closer to 95F (35C) vs the traditional 72F (22C). So jumping up a little more is maybe not super exciting, but it's still innovation.

mistercow 15 hours ago [-]
And I think the answer to the "doing the math" question is, until you've actually collected the data, "what math?" Until someone actually puts a bunch of six-figure value hardware through its paces, pushes the previous limits, and sees what that does to its lifespan, there's nothing to meaningfully calculate.
gleenn 16 hours ago [-]
And the fact that their system doesn't dump water. I think that is actually perhaps the bigger deal. Datacenters have been getting a lot of heat (pun intended) for using significant fresh water at the expense of local municipalities.
frollogaston 16 hours ago [-]
Closed-loop water cooling chips is nothing new. There are two separate water systems that often get conflated*. The loop warms up the water, which is recycled but first needs to be cooled externally somehow. Normally they use evaporative cooling towers that do use water, or chillers that don't use water but use more energy. But they're claiming they can get that water loop so much hotter than the outdoor environment that active cooling isn't needed. They attribute this to improving the chip-to-water interaction.

Even air-cooled datacenters work somewhat the same way, but instead of water to chips, it's air. The air goes into hot aisles then exchanges heat with water, after which, see above.

* Other datacenter marketing materials talk about how they have a "closed loop system that uses no water" and they do still use water in the evap towers. I was half expecting this article to be that again, glad it wasn't.

XorNot 15 hours ago [-]
Just because it's not new doesn't mean that it was available or that the engineering needed to bring it to mass market wasn't significant.
frollogaston 15 hours ago [-]
It was available, there are plenty of water-cooled datacenters already, or water-cooled racks fitted into existing sites. Nvidia improved the cooling efficiency though.
loeg 17 hours 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.
frollogaston 15 hours ago [-]
Doesn't look like they made the hardware more tolerant of temperature, rather they made it remove waste heat more quickly.

"NVIDIA’s thermal engineering team reworked how those components handle heat, designing cooling loops that simplify how liquid is routed to multiple high-power chips on the board using a single inlet and outlet, resulting in a cleaner tray-level cooling architecture"

AlotOfReading 16 hours ago [-]
Nvidia's automotive and aerospace variants get ratings up to 85C, for comparison.
taneq 16 hours ago [-]
Don’t their consumer GPUs run at 85C core temp? Maybe not for as long though.
NekkoDroid 15 hours 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 15 hours ago [-]
Core temp though. Ambient temp is a different story, and also depends on air vs water. In fact the article suggests the difference is getting the water more directly onto the chips, no mention of running at a higher core temp.
AlotOfReading 15 hours ago [-]
Temperature ratings are the allowed ambient temperature. The actual silicon will inevitably operate somewhat higher, because coolers are just moving heat down a temperature gradient.
sheepscreek 15 hours ago [-]
Speculating here - “effectively” cooling the CPU and GPU materially using this technique at datacenter scale may have never been done. Those things than run hot, easily crossing 100C. So the loop is doing a lot of work to keep them stable at 55C.

The innovation may be in the speed or volume flow of the coolant through different parts of the data centre to regulate the temperature. And of course, redesigning every component to be compatible with this fan-less design.

I think it’s only possibly because NVIDIA is much more vertically integrated than ever before.

joe_the_user 12 hours ago [-]
There's never been a reason a sealed water-cooled system ever had to use vast amounts of water. But State Of The Art wound up being using and expelling the water. It seems like data centers operate like other industrial enterprises - locate in the city/county/state that gives you carte blanche, do whatever is convenient, get used to the idea that this the only way things can be done.

So a multitude of communities rebelling and complaints about environmental damage fell on deaf ears but a technical spec might be paid attention to.

voxelghost 12 hours ago [-]
Ai slop from Nvidia, who would have thunk.
taneq 16 hours ago [-]
Is this not how it was already done? Huh.
kayo_20211030 19 hours 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 19 hours 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-supercompute...

kayo_20211030 18 hours 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 :-)
hommelix 12 hours ago [-]
Come now to south of Germany. We are in the middle of a 10 days heatwave at 35 degC on average.
dindresto 5 hours ago [-]
38°C in Mannheim today. Might go above 40°C on Saturday, which never happened here before.
mattmanser 18 hours 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 18 hours 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 8 hours ago [-]
Yeah early this year I've had the coldest winter in years and now the hottest summer in years.
matt-p 18 hours ago [-]
Yeah, this is part of the issue to be honest. You'd need outdoor air to be below ~37°C to guarantee 45°C water outlet temperature. In most locations you still need cooling towers or compressors some of the time, so you still have to build all the infrastructure that comes with them; though reducing their use is still great, saving serious amounts of water or energy.

For e.g you might think of the outskirts of London as fairly moderate, but this week it's been hot enough that supplemental cooling would likely have been needed at points. For a data centre here you'd typically design the cooling system to cope with outdoor temps in excess of 40°C, which is not a conservative number anymore.

Also, while Nvidia might be happy with you supplying water at 45°C I suspect you will get better longevity of the hardware at lower temps like say 35°C. GPUs are expensive, and extending longevity may well be 'worth' a bit more water or energy to you. In practice you are also likely to have air cooled systems that sit 'beside' the AI compute like storage severs, any extra CPU compute and network switches. So you are likely to need a separate room and cooling system for that. Great progress though.

frollogaston 15 hours ago [-]
So they only have to actively cool when it's above 98˚F outside, that's still way better than what they do now
matt-p 14 hours ago [-]
Definitely!
17 hours ago [-]
maerF0x0 1 hours 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 ...

frollogaston 4 minutes ago [-]
The entire room wouldn't be 45˚C, or even the entire machine, just the liquid-cooled components.
interactivecode 1 hours 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.
randallsquared 5 hours 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 4 hours 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 2 hours 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
metabagel 18 hours 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-...

https://www.nas.nasa.gov/assets/nas/pdf/ModularSupercomputin...

rswail 9 hours 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?

Toutouxc 8 hours 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.

t0mpr1c3 23 hours ago [-]
with efficient heat exchange you could get the coolant up to mash temperature (65C) and run a combined data center/brewery
johnsocks 2 hours 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?
sabareesh 17 hours 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/
amoshebb 6 hours 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?

justsid 2 hours 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.

joxdosba 6 hours 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.

rglover 1 hours 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/

[2] https://thermify.cloud/how-it-works/

vladar107 9 hours 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 9 hours 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.

Dead_Lemon 6 hours 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.
VorpalWay 18 hours 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?

loeg 17 hours ago [-]
Evaporative cooling consumes less expensive electricity than air conditioning. Electricity is much more expensive than water (for the same cooling load) in most places DCs are located.
7 hours ago [-]
rnxrx 18 hours ago [-]
It’s usually open loop - closed loop, so closed loop goes through CRACs or liquid cooled equipment manifolds. That heated water circulates through an heat exchanger on the roof that uses open loop cooling to shed the heat to the surrounding environment.
bozhark 17 hours ago [-]
How inefficient
cl0ckt0wer 17 hours ago [-]
Way more efficient, that's why they do it. Evaporating water carries an enormous amount of energy.
quickthrowman 17 hours ago [-]
It uses almost half as much electricity, it’s way more efficient than air cooled chillers by themselves.

East of the 100 degree W line of longitude, there is more than enough water to use evaporative cooling if needed.

Groxx 17 hours ago [-]
(ab)using fresh water in vast quantities is cheaper.

currently.

and also more energy efficient, because evaporating water away takes a lot of energy with it. you have to raise radiators to a higher temperature to keep up with that, or have much more surface area.

loeg 17 hours ago [-]
There's just a lot of fresh water almost anywhere you'd want to site a DC. In places where water is more expensive, obviously it doesn't make sense.
dsp 17 hours ago [-]
It’s very efficient. The net electrical energy saved using the latent heat of water is 30 to 100+ times greater than the energy required to desalinate or wastewater recycle the same volume of water.
derac 18 hours ago [-]
the unfathomable reason is that it is significantly more energy efficient.
bozhark 17 hours ago [-]
Then it’s not being measured adequately.

The loss of material must be included

If water is evaporated or spent out of the system.. it is not more efficient

danstiner 17 hours ago [-]
It is more efficient, in terms of cost the datacenter owner pays per unit of heat extracted. Water is cheap in places this is being done, relative to amount of heat vaporization can carry off.

You can certainly argue DCs should pay more for water than other uses, but who gets to decide what is a good vs bad use of water? Pricing in externalities is tricky, and water usage rights are especially complicated. I don't know what a good&fair solution is.

sebzim4500 2 hours ago [-]
I would guess that evaporative cooling is usually still cheaper even if you price in externalities. In most of the world there isn't really a shortage of water.
hiddencost 17 hours ago [-]
Companies will never price in externalities unless they are forced to.
1e1a 18 hours ago [-]
Yes, they are using evaporative cooling.
bozhark 17 hours ago [-]
But you can do that in a closed system and recapture the water
quickthrowman 17 hours 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 9 hours 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.

Brian_K_White 16 hours ago [-]
That is called a heat pipe and doesn't get you anything. It's exactly the same as a closed plain water loop with no phase-change involved.
danielheath 16 hours ago [-]
At the scale DCs are operating at, losses from flexible tubing are not negligible either.

1gw of power converts approx 400 liters of cold water into steam _per second_.

2OEH8eoCRo0 16 hours ago [-]
Evaporative cooling is practically a cooling cheat code. Why unfathomable? What's more efficient?
danans 16 hours ago [-]
Not more efficient at heat dissipation, but radiative cooling panels can achieve sub-ambient dissipation in conditions (like high humidity) that evaporative cooling performance declines in, and with no water consumption.

https://www.sciencedirect.com/science/article/abs/pii/S13594...

prng2021 16 hours 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?

dgacmu 14 hours 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 3 hours ago [-]
Can you explain what PUE stands for? I am lost.
dgacmu 2 hours ago [-]
Sorry! Power Usage Effectiveness. It's a measure of the overhead of delivering power to the servers (or motherboards, depending on how you measure it), taken to include all other datacenter power overheads: AC/cooling, UPS losses, and sometimes transformer/rectifier losses.

A PUE of 1.2 means that for every watt of power you're using in a server, you're using 1.2 watts drawn from the grid (approximately). Those extra 0.2 watts are being spent on cooling and other things.

samarthr1 8 hours ago [-]
I understood that to mean zero steady state water consumption?
vkou 16 hours 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.

dialogbox 16 hours 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 14 hours 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.

eptcyka 6 hours ago [-]
What's the reason we can't use heat pumps here to turn that waste heat back into electricity?
krab 6 hours 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).

nialse 1 days 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 1 days 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 1 days 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 1 days 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 1 days 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.
amluto 1 days 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 1 days ago [-]
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.

lkbm 15 hours ago [-]
This is kinda debunked / obviously false. It's almost entirely a land use issue: a building will create a heat island. Data centers aren't using enough energy to make a significant difference.

More on it at [0], but it doesn't take anything beyond a basic energy calculation to know that 1GW of energy is not going to have a significant effect "6.2 miles away".

[0] https://andymasley.com/writing/data-centers-heat-exhaust-is-...

amluto 22 hours 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.

RicoElectrico 1 days 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.
fwipsy 15 hours 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 3 hours 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?

uberex 18 hours 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.
mips_avatar 13 hours ago [-]
My GPUs at home produce 60°C water. I just wish I had a good use for them.
billjive 10 hours ago [-]
“Near” zero??

Leslie Groves, Oppenheimer

blondie9x 13 hours 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/

Is this NVIDIA lawyer trying to influence the public perception of datacenter for his company?

sourcegrift 13 hours ago [-]
I'm worried about the carbon footprint and other impacts of the higher temperature
htrp 1 days ago [-]
wasn't this announced at gtc in march?
emsign 17 hours 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 15 hours 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 Golf courses used 2 trillion liters in 2020. We won't even bring up almond production.
emsign 15 hours 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 5 minutes 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.
m3kw9 19 hours ago [-]
This is what PC heat sinks uses. Someone could have thought of that
crypttales 2 hours ago [-]
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qsxfthnkp2322 1 days 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?

palmotea 1 days 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?

The shareholders desperately need that money.

falcor84 3 minutes ago [-]
You make it sound silly, but yes, as a (very small) shareholder of NVDA, I would indeed prefer that they use Claude to write blog posts rather than hiring a dedicated person to do that with "marketing flair". Better yet, I would prefer that they just publish the prompt with the actual update details and I'll take it from there.
jazzyjackson 1 days ago [-]
Their valuation is based on their software stacks’s ability to displace human labor, this is just them eating their dogfood.
qsxfthnkp2322 1 days 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 1 days 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 1 days 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)

Animats 17 hours ago [-]
We're there. The recent HN article about the Fender Stratocaster had some content from a Fender press release, which was regurgitating text from a legal aggregation site. It was, overall, bad coverage of the area of copyright on decorative but useful objects.[1]

Watch for cases where content has been through two layers of LLMs. It's not good.

[1] https://news.ycombinator.com/item?id=48665916

Quin_Liu 12 hours ago [-]
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mv_d5339e31 15 hours ago [-]
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transformerash 1 days ago [-]
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mchusma 23 hours 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 23 hours 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
signatoremo 18 hours ago [-]
What do you think of China, also dumb, or just blindly FOMO?

https://spacenews.com/china-backs-orbital-data-center-startu...

https://www.reuters.com/science/china-vows-develop-space-tou...

Plans for space data centers should be seen with skepticism. However when they are backed by different parties who have stakes in the game, that's more credible. More than HN crowd for sure.

msla 17 hours ago [-]
OK, here's my problems with space data centers. How many of them has China solved?

1. Space is terrible for heat regulation. It's a perfect insulator for everything except radiative cooling, which is the least efficient. Hot things stay hot.

2. Space is full of radiation. Everything has to be radiation hardened, which makes it heavier, more expensive, and, yes, more difficult to cool.

3. Space is far away. Well, farther than a data center on Earth can be. I know China hasn't solved the speed of light.

We put up with it with satellites because it still has some advantages over trying to run cables literally everywhere, but we do, in fact, still use cables laid on the bottoms of the oceans.

So, is physics wrong, or is a country known for making dumb decisions some times making a dumb decision?

frollogaston 15 hours ago [-]
I would comfortably bet at least $1000 that this is bs, and it would be more money than China has put in so far. They've got a "vow."

To answer your first question, yes. Even if they were US companies. Remember when each Big Tech player was claiming to build their own blockchain, except centralized which was a contradiction.

wolvoleo 21 hours ago [-]
I honestly think musk wants them there because they are hard to reach.

I do really think that if large numbers of jobs are indeed going to be displaced by AI, movements will pop up of people attacking datacenters (and honestly I wouldn't blame them even though it won't really accomplish anything). Having them in space keeps them out of reach of anyone but state actors.

battery_staple_ 22 hours 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 22 hours ago [-]
Starlink is already a space based datacenter. No one is up there maintaining it.
wolvoleo 21 hours ago [-]
It's not, it's more like a space based network, the processing and storage is minimal.
asdff 21 hours 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.
wolvoleo 21 hours ago [-]
If you look at how small a Starlink sat is, and how much of that space is taken up by power generation and storage, antennas, signal conditioning, RF electronics and more, I'm sure that whatever resources are running the computing in the entire starlink fleet orbiting the world can fit all together in one single row of servers in an existing datacenter.

And yes, a space-based computing node would not need quite as much of some of these things but they'll still need them in some way. It's not like you can just plug in a power and ethernet cable into them.

I doubt this will scale to a level that is actually useful. It's a nice experiment, just like Microsoft when they threw a datacenter container into the ocean. But not practical in the current conditions: https://news.microsoft.com/source/features/sustainability/pr...

Yes they say it is amazing and sustainable there in that blog post, yet somehow they've never bothered to do it again.

asdff 20 hours ago [-]
They can't make them a little bit bigger? But also I found this interesting image on the scale at hand here of a given launch of starlinks, no clue how many are included in a single launch, and it is a substantial amount of rack space they have been sending up at once:

https://i.redd.it/zh7qvyfqgvx21.jpg

So to me they have solved the issue of having a space based compute array network interfacing with the earth. They have solved the issue of launching and deploying this array. And their given launches seem to have a substantial payload of compute going up at once just in sheer volume. And right now the only real difference is that the nodes they are launching are just pretty weakly specced. Everything else is in place and turnkey.

wolvoleo 17 hours ago [-]
But most of that is nothing to do with compute. A rack of servers is all compute. Starlink sats are antennas, RF amplifiers, solar panels, laser links, shielding, even maneuvering thrusters and fuel for those (they could be electrical ion thrusters but they'll still need reaction mass, not sure what type they use). Probably some inertial reaction wheels too, they are used for spacecraft orientation, not positioning.

They are sending a few racks of stuff up every launch but the problem is not that it's underspecced. It's that most of it is just needed for equipment survival and communication in space.

You're talking about an environment that's full of radiation and goes from -200C to +200C every 90 minutes. That needs to be orbit managed and cooled (and sometimes also heated) without any airflow. Just sticking a few servers in a barrel isn't going to do the job.

dgellow 21 hours ago [-]
A datacenter is about data. Your network of space router is in no way something a reasonable person would consider a datacenter... Even less an inference datacenter.
asdff 21 hours ago [-]
Why, because on board storage is too small and the compute nodes are underpowered? And that can't ever change? A reasonable person doesn't understand technology usually. That is increasingly an understanding left to the wizard class.

I mean people make clusters out of raspberry pis and minipcs.

dgellow 19 hours ago [-]
There is nothing magical here, you definitely don’t need to be a wizard to understand the hardware necessary for AI inference. You can make nice little clusters with rpis, yes, there is nothing magical about that, it’s pretty much baremetal 101. But no, you cannot run any meaningful inference on that cluster.

Maybe look at what is inside a datacenters, the amount of power required is very large, and the hardware to run the inference + network isn’t small. Then try to see how much sending that to space cost

frollogaston 15 hours ago [-]
This only makes sense if the compute nodes only become more powerful in space in the future and not also on the ground.
wasabi991011 19 hours ago [-]
> Why, because on board storage is too small and the compute nodes are underpowered?

Yes

> And that can't ever change?

It can, but but not for free. As the comment earlier in the thread was referring to, more computing power needs more cooling, and cooling in space is hard.

> A reasonable person doesn't understand technology usually.

What? Do you mean a layperson? Why does that matter when discussing the feasibility of space-based AI datacenters?

> That is increasingly an understanding left to the wizard class.

No, you can get there with a bachelor's degree in a relevant subject. Or just reading informative news sources.

> I mean people make clusters out of raspberry pis and minipcs.

So? What does that have to do with anything?

BuildTheRobots 21 hours ago [-]
> Anything in space is more expensive and way harder to do, for a datacenter there is no benefit.

If we pick an extremely fast orbit, then relativity means the hardware will age out (slightly) slower, so I'm sure that'll help with the maintenance issue.

It's the wrong way around though. Ideally we want to speed up our current compute ability not slow it down; if it experiences more time than we do then it can do more. Relative-MHz means my slower hardware becomes tangibly fast again.

General Relativity says mass warps space time, so we need to get these datacentres out of the Earth's gravity well. And the Sun's, and the Milky Way's; out into the deepest void of intergalactic space. The good news is that a maintenance callout is still quicker than some of the earth based DC's I've had gear in, but the bad news is that it doesn't get us much of anything at all.

Special Relativity lets us abuse time with speed (something I discovered as a teenager). Going faster than Earth means we experience less time, so we just need to try and slow down comparative to our home base. The earth is orbiting the Sun at ~30km/s, the solar system is orbiting the centre of the Milky Way at ~230km/s and our local group of galaxies is moving relative to the Cosmic Microwave Background at ~600km/s. We can easily get our DataSpaceCentre up to 1,000km/s or more, so we just need to point it relative to all that movement we mentioned above making stationary relative to the universe. It's completely doable, but (as well as far more variable response times to callouts) only gets us an extra second of compute over a human lifetime.

Fundamentally, we're attacking this problem in the wrong direction. Earth's gravity is comparatively minor, and our piddly ~600km/s relative movement is a tiny fraction of the speed of light. We should be filling The Earth with compute, and then decamping humanity into space and travelling at relativistic speeds. Or put the compute in space and move the Earth into the event horizon of a black hole. You can't do the inverse of Interstellar keeping Earth where it is, the maths isn't in our favour. If everyone lived on (a less moist) Miller's Planet, we'd get 7 years of compute every hour. It puts Moore's Law to shame; the relative MHz are obscene.

There's the obvious problem of communications. I'm led to believe there's issues with radio and light, so this probably isn't a job for fibre. Veritasium seemed to imply a battery, switch, lightbulb and a wire stretching around the globe would light instantaneously, so I'm sure we can come up with a new copper Ethernet standard for low latency over solar distances.

Invest early, we're going straight past the moon!

dgellow 19 hours ago [-]
You’re surprisingly good at this, ngl
rswail 9 hours ago [-]
Space based data centers make no economic sense compared to land based.

The only reason is to remove them from local/regional, and potentially national/international jurisdictions.

Oh, and of course, the other reason is to give SpaceX to have a reason for xAI to be part of its structure.

Starlink makes sense, LEO comms using a mesh makes sense.

LEO/geosync satellite data processing doesn't.

frollogaston 15 hours ago [-]
This relies on transferring heat to the outdoor air. Can't do that in space.
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