Sapphire: A Liquid That Won't Get Things Wet

eaglebtc writes "Tuesday on Good Morning America, a representative from Tyco Fire & Security demonstrated an amazing new substance called Sapphire: a water-like fluid that does not get things wet. He filled a small fish tank with Sapphire and submerged a book, a laptop, and a flat panel TV. Both electronics were turned on when submerged; all three items came out completely unharmed. Click here for a slideshow of the demonstration. The official name for Sapphire is actually Novec 1230. Read about it here (PDF). Tyco sees practical applications of Sapphire in fire extinguisher systems for museums and libraries. By the same token of practicality, regular readers of Slashdot probably have something else in mind: total-immersion watercooling. Just think of the possibilities!"

"Water"-cooling

[Liselle]

Offtopic, but the submitter opened the door: according to their specs sheet [mmm.com] (PDF warning), this stuff has a boiling point of 49.2C (120.6F). Processors burn hotter than that, how useful would it still be for cooling purposes if it were a gas? I also have to wonder what the long-term effects of exposure would be... it's one thing to dunk a laptop for a few seconds, it's something else entirely to have it swimming all day long. At least your machine would never catch on fire.

They might have some information there about how well the stuff will conduct heat, but I got a lousy grade in Chemistry, so I'll leave it to the experts. ;)

Freezing temperature

[akaina]

A very interesting note is that Saphire/Novec 1230 has a freezing point at -162.4*F according to 3M's white paper

Hasn't this been done before?

[PeterChenoweth]

I remember watching a show called "Beyond 2000" on the Discovery Channel years and years ago (1995ish?). I remember an episode where they had a tank of some liquid that they submerged a TV into.

So is this concept of non-conductive-water-like substances all that new?

Distilled Water?

[tvh2k]

Wouldn't distilled water work just fine for total-submergion water cooling? After all, it's the ions in water that make it a conductor, correct?

here is a video

[Anonymous Coward]

of the chemical in action [3m.com].

Read the PDF

[Ralconte]

This was on Fark already. Read the PDF. It's stored as a liquid in the tank, but its a cyclic fluorocarbon that vaporizes on release. This is simply the latest version of Halon (TM) fire extinguishers, not an "non-wetting water" or an "non-flammable organic with a water-like viscosity" At work we have carbon dioxide jets in the server room in case of fire. We've never had the building burn down so I don't know the merits of either method.

Re:"Water"-cooling

[Frymaster]

If they're using it to put out fires, it's a safe bet that it can handle your Athlon.

yes... but no-one's concerned about reusing the water you used to put out the fire. coolant, on the other hand, should stick around for more than a few seconds before it bubbles off into the atmosphere.

Fluorinert

[Winter]

This is of course not the first liquid that does not cause harm to electronics, and can be used for total immersion water cooling. Fluorinert (3m) [3m.com] has been around for a while. One version of it is(was) also used for liquid breething deep diving (same as used on "The Abyss").

Re:Distilled Water?

[dreamchaser]

The short answer is no. Distilled water has far less conductivity but it still is a conductor.

Specs Data

[Liselle]

Here, I pulled it before /. nuked the site:

Chemical Formula CF3CF2C(O)CF(CF3)2
Molecular Weight 316.04
Boiling Point @ 1 atm 49.2°C (120.6°F)
Freezing Point -108.0°C (-162.4°F)
Critical Temperature 168.7°C (335.6°F)
Critical Pressure 18.65 bar (270.44 psi)
Critical Volume 494.5 cc/mole (0.0251 ft3/lbm)
Critical Density 639.1 kg/m3 (39.91 lbm/ft3)
Density, Sat. Liquid 1.60 g/ml (99.9 lbm/ft3)
Density, Gas @ 1 atm 0.0136 g/ml (0.851 lbm/ft3)
Specific Volume, Gas @ 1 atm 0.0733 m3/kg (1.175 ft3/lb)
Specific Heat, Liquid 1.103 kJ/kg°C (0.2634 BTU/lb°F)
Specific Heat, Vapor @ 1 atm 0.891 kJ/kg°C (0.2127 BTU/lb°F)
Heat of Vaporization @ boiling point 88.0 kJ/kg (37.9 BTU/lb)
Liquid Viscosity @ 0°C/25°C 0.56/0.39 centistokes
Solubility of Water in Novec 1230 Fluid <0.001 % by wt.
Vapor Pressure 0.404 bar (5.85 psig)
Relative Dielectric Strength, 1 atm (N2=1.0) 2.3

Re:"Water"-cooling

[M1FCJ]

A boiling substance is a brilliant coolant. Boiling uses a lot of energy and this can result in very large temperature drops. A refrigeration system where the substance gets boiled by a pressure drop is perfect (all fridges work this way). Also it will keep your CPU at a fixed temperature which is quite desirable. On the other hand I haven't seen the P-T diagram of this fluid so I can't comment if this is suitable or not as a refrigerant coolant.

Re:"Water"-cooling

[WolfWithoutAClause]

Provided the fluid was allowed to circulate, a boiling point at 49.2C should actually be pretty good- the fluid will give you micronucleation boiling and that will leverage the latent heat of vapourisation to carry away heat.

You're only going to get big problems if the processor reaches about 70C- then the boiling will become film- and you'll get an insulating gas layer- (the density of the gas is almost 100x lower than the liquid- and the thermal coefficient is much the same), so shortly after that your processor will fail (hopefully just the thermal protection kicking in, but don't mess with this stuff if you have an early AMD :-) ).

One good thing about this fluid is that you can refrigerate it down to -100C with it still being a liquid. That's very nice for overclocking purposes.

How is that new?

[Eric Smith]

Fluorinert [3m.com] does the same thing, and it's been around for many years. That's what was used in some Cray machines.

Re:Chemical properties

[sacremon]

In addition the stuff is photolytic by UV light. The PDF states the stuff would be expected to last about five days when exposed to the atmosphere. Fluorescent lights put out a fair amount of UV, so if it were used for cooling, it would have to be a well-sealed opaque tank.

Re:Safe?

[jspoon]

Tell that to the NCO's in Viet Nam who had to drink glasses of Agent Orange to show the men it was safe. Many had children with severe birth defects, assuming the stuff didn't make them completely infertile.

Re:Slideshow was made of Sapphire as well

[dominator2010]

You have to open the slideshow by clicking on the link between the short opener in bold and the beginning of the article. Here's the link [go.com] Look for the link "IMAGES: Liquid in action on Good Morning America" in between the two.

Re:Fluorinert

[Anonymous Coward]

MSDS for Fluorinert [sisweb.com]. All it says is avoid prolonged exposure to vaporous Fluorinert

Re:Specs Data

[SlayerofGods]

So if it is 1.103 kJ/kg C and water is 4.18 kJ/kg C
Water is about 4 times better, eh?

Re:"Water"-cooling

[Chiasmus_]

If this stuff boils in the fire it will cool even better because of the latent heat of vaporization. The vapor will help exclude oxygen, too.

And that's just great, until the building fills up with five hundred degree anoxic Sapphire steam.

See, the reason that sprinkler systems are popular is that they tend to preserve human life. Unfortunate drawback: they fry electronics.

Conversely, the reason that Halon is popular is that it tends to preserve electronics. Unfortunate drawback: it tends to kill people.

It seems that Sapphire is not the holy grail of fire prevention: a system that will save both your NOC and the geeks inside it. Somebody ought to try to come up with that. There's probably a lot of money there.

Re:"Water"-cooling

[random coward]

According to the fact sheet, this is meant to put out fire by lowering the temperature below the burning point, not by preventing oxygen from combusting the fuel. So it is the same thing, in fact.

UV Light

[Anonymous Coward]

The PDF says it breaks down quickly under UV light...

Re:If it doesn't get things wet...

[Raunch]

> how to you clean it up?

From the article:
The fire protection fluid will quickly evaporate, safeguarding
these items - and leaving them unaffected.

Immersion won't work.....

[lhaeh]

Not for long anyways, heres the rundown of tryed and failed experments:

-immersion in tap water: its conductive, one person was stupid enough to try this on his shiny new system, lets just say the power supply did somehting intersting.....

-immersion in distilled/de-ionised water: it gets contaminated by the computer and becoms slightily conductive, all the traces corrode.

-immersion in mineral oil: works for a few days but then stopped working with no obvious damage. Probily the capacitors soaked up the oil and that changed their electrical properites.

So theonly this stuff will work is if you use some kind os sealent on the board around the capicators and that might not even work...

Evaporation...

[Benm78]

Take a look at these specs:

Boiling Point @ 1 atm 49.2 C
Heat of Vaporization @ boiling point 88.0 kJ/kg
Vapor Pressure 0.404 bar

This is a liquid that will readily evaporate (a little slower than ether would). If a limited quanitity is used (such as in a hand-held extinguisher), it will probably evaporate before you get the chance to clean it up.

The article also states that the LC50 is over 10% by volume, which tells this substance is probably not very dangerous, unless specific medical problems arise.

As it seems to be safe to the atmosphere as well, i guess the 'plan' is to just let it sit there and evaporate.

This may sound dangerous, but we do the same with CO2 - which is more lethal to anyone entering the room and possibly to the environment (global warming) as well.

Re:"Water"-cooling

[Laur]

You could always do a cooling tower like system. The saphire boils, turns into a gas, and then in the cooling stack condensates back into a liquid.

That is not a cooling tower. A cooling tower works by evaporating a liquid (usually water) to a gas and then just venting this to the atmosphere. It is not a closed system. BTW, this is why cooling towers have visible clouds of steam rising from them on cold days. What you are describing is a simple refrigeration circuit, such as what is used in your fridge or AC unit. The refrigerant is evaporated in the evaporator inside your house, absorbing heat, and condenses back into a liquid in the condenser located outside, giving off heat to the environment.

Re:Evaporation...

[the eric conspiracy]

Vapor Pressure 0.404 bar
LC50 is over 10% by volume

Yikes! At room temperature in a closed room this stuff would be present at 40% by volume!

This stuff is quite dangerous.

They say no ozone risk

[billstewart]

Their PDF blurbs talk about the ozone question, and say that the stuff breaks down in about 5 days in sunlight and doesn't bother the ozone. It doesn't say exactly what happens to the Fluorine in the process, but it does say that it's much different from the hydrogen-fluorine-carbon compounds like Freons. From what I remember, the freons catalyze the breakdown of ozone; perhaps the breakdown products from this compound don't do that (e.g. maybe the fluorine atoms all end up as F2.)

Re:Another liquid that won't get things wet:

[Anonymous Custard]

Okay, chemistry geeks, it's:

1,1,1,2,2,4,5,5,5-NONAFLUORO-4-(TRIFLUOROMETHYL)-3 -PENTANONE

Anyone know if that's conductive?

Re:Safe?

[HeghmoH]

Asinine is defined as "Utterly stupid or silly." Doesn't that disqualify true statements? Caffeine [wisc.edu] is more [coalition21.org] toxic [uic.com.au] than [pitt.edu] plutonium [magma.ca].

Re:"Water"-cooling

[Myrrh]

Actually, it is the same thing.

Fire suppression systems such as those that use Halon (which was outlawed in the '90s due to its ozone-destroying side-effects) put out fires by displacing oxygen with some other gas.

Spraying water on a fire does not "deprive" the fire of oxygen. In fact, this is why you aren't supposed to fight certain types of fires (a magnesium fire, for example) by spraying water on it. That's because if the fire is hot enough, it will "crack" the water molecules, liberating both oxygen and hydrogen -- which will of course make the fire much worse.

Spraying water on a fire robs the fire of thermal energy. Evaporation (converting a liquid to a gas) is an endothermic process; it takes a significant amount of energy. When you dump a bunch of water on a fire, it takes energy from the combustion reaction to turn the water into steam. Eventually so much thermal energy has been taken from the fire that the fire extinguishes.

Finally!

[dj245]

Finally the development "A Liquid That Won't Get Things Wet" is complete and it can join the ranks of the pedigree of advanced fluids such as Liquid that you can immerse running computers in [fnal.gov] and Liquid you can breathe in [scienceweb.org]

But when will we have "Liquid you can drink and not be accused of modding on crack"?

total immersion cooling

[MoFoQ]

It's only useful in total immersion cooling if and only if it's cheaper than fluorinert (by 3M).
Of course, due to the low boiling point of Sapphire, it would be necessary to isolate the cpu and probably the gpu and cool them with normal watercooling and the rest can be submerged in sapphire, which will also help reduce the build up of dust, enemy of efficient cooling.

BTW, TIC is nothing new. There are these crazy New Zealanders who bought 2 gallons of fluorinert, priced at 500 bucks a gallon (and you thought gas prices in california was bad), submerged their entire setup in it and cooled the liquid.
Unfortunately, LN2's temp was well below the freezing point of fluorinert. Here's a linkie [octools.com]

I think you need to re-read the pdf...

[sean.peters]

It specifically states that it's NOT like HALON - it puts out fires by cooling vs. interference with fire chemistry (as HALON does). And it can also be used in "streaming" applications (like water).

Sean

Re:"Water"-cooling

[asavage]

The heat capacity is 1.1kJ/Kg Kalvin so about 1/4 that of water. It's freezing point however is -108 C so it could could be easily used at -30 or -40 to keep everything nice and cool. It would also insulate some of the sound I expect.

The MSDS sheet shows the facts

[TheDigitalOne]

The MSDS sheet for ansul is here: http://www.ansul.com/docs/msds/F-2003263.pdf

Specific Physical Form: Liquid

Odor, Color, Grade: clear colorless, low odor

General physical form: Liquid

Autoignition temperature Not Applicable

Flash Point Not Applicable

Flammable Limits - LEL Not Applicable

Flammable Limits - UEL Not Applicable

Boiling point 46C

Vapor Density 11.6 [RefStd: Air=1]

Vapor Pressure 244mmHg [Details: @20C]

Specific Gravity 1.6 [RefStd: Water =1]

pH Not Applicable

Melting Point -108C

Solubility in Water None

Evaporation Rate >1 [RefStd: BUOAC=1]

Volatile Organic Compunds No Data Available

Percent volatile 100%

VOC Less H20 No Data Available

Viscosity 0.5 centiposise

Bad idea.

[Anonymous Coward]

One problem. Try heating a frying pan with nothing on it. After you can sense that it's hot enough, sprinkle a little water on it. The water will float over the pan.

When the water makes contact with the hot pan, it turns to steam, which then insulates the remaining water above the pocket. The temperature of that pocket of steam gets quite high since it has little opportunity to escape and doesn't really get cooled. More importantly, the pan gets very little cooling effect from the water evaporation.

Therefore, you should never rely on coolant when any part of it is at or very close to its boiling point. The coolant properties of the fluid break down.

The above doesn't really match your example, since it's not immersed within a coolant environment. For a better example, use a boiling pot of water. Examination of the locations of steam nucleation reveal that those areas (however small) do not get wet, and gets insulated as illustrated above.

Stupid idea

[khrtt]

Go back and read the datasheet. This saphire stuff has very low heat of evaporation. Basically, it's designed to boil off right away when you pour it on fire. It has high vapor pressure, which allows a large amount of it to stay in gaseous form mixed into the air, extinguishing the fire by oxigen displacement. A good coolant, on the other hand, would have a high heat of evaporation and low vapor pressure, like water. Water puts out the fire by using up the thermal enerrgy on evaporation and cooling down the materials, not by oxigen displacement. If you want submersion cooling, look for something that won't evaporate easily.

Re:Specs Data

[Cecil]

I am not a chemist, but you do know that CFC stands for 'chlorofluorocarbon' right? As in, Chlorine, Flourine, and Carbon? Where in that chemical composition do you see any chlorine? It's not a CFC just because it has the letters 'C', 'F', and 'C' in it somewhere.

Which isn't to say fluorine is pleasant stuff, but it's not going to destroy the ozone layer.

Re:Specs Data

[Handpaper]

For the chemically-challenged: CFC stands for Chloro-Fluoro-Carbon.
That means that the compound contains Chlorine, Fluorine and Carbon.
This compound is a Fluorocarbon - it contains no Chlorine. The C in the formula represents Carbon.
As for the EPA, according to page 2 of the PDF, they are already considering it - and since the product was developed as a greener replacement for CFC-based fluids, it probably has a good chance of acceptance.

Re:"Water"-cooling

[casehardened]

You mean, like...mineral oil? I know a guy who put his entire motherboard in an aquarium tank of mineral oil; it's non-conductive, has reasonable heat transfer, and won't dissolve PCB's. Only problem was that hardware changes were...messy

Re:Evaporation...

[Lumpy]

This may sound dangerous, but we do the same with CO2 - which is more lethal to anyone entering the room and possibly to the environment (global warming) as well.

that is just plain funny! let's look shall we?

MSDS for C02 [weldingsupply.net]

Health Haz Acute And Chronic: INHALATION:SIMPLE ASPHYXIANT.HIGH
CONCENTRATIONS IN AIR CAN REDUCE OXYGEN NECESSARY TO SUPPORT LIFE.

The EXACT same health hazard as water... damn dangerous stuff there!

after researching it, More CO2 is released into the atmosphere by human beings simply opening and consuming Carbonated beverages and breathing than is released by firefighting every day. please RE READ that line again... you EXHALE Carbon Dioxide and it is in your beloved pop.

Please get your fact's straight before you start fearmongering...

Re:Fluorinert

[praedor]

Eh? Rats (dogs, cats, cows, horses, skunks, ...) do NOT have a different respiratory system than humans. They work exactly the same, by the same mechanisms, and for the exact same purpose. Birds are mechanically a little different but their lungs work the same way too.

It is real stuff and it works. It did not kill the rodent. It could be a temporary hazard for developing pneumonia after the fact if the lungs don't clear the liquid soon enough and a bacteria can get started in it.

Basically, expell the liquid and then cough, cough, cough to clear most of it, then slowly eliminate the rest the same way your lungs clear mucus contaminated with dirt, bacteria, viruses, etc.

Re:"Water"-cooling

[fintler]

It makes me wonder why they haven't developed hard drives to work in a vacuum.

Hard drives work because air is there. The head basically "takes off" in a sense. It flys above the platters. In a vacuum, the head would just drag along the platter, probably destroying the drive.

Done since.. like... 1920

[poptones]

All it takes is a tank of Mineral oil. Mineral oil has been used to cool electronic components since there WERE electronic components. I'm surprised no ham has chimed on on this yet - a "dummy load" antenna is little more than a bigass resistor submerged in a gallon pail of mineral oil, and one of those things will take several hundred watts of RF energy before overloading.

I've seen submerged mineral oil cpu boards before. Heck, here's one right here [2cpu.com] at the very top of the Google [google.com].

Re:Fluorinert

[Just Some Guy]

I saw the same demonstration on "Late Night with Johnny Carson" a long time ago with my dad. A scientist dropped a rat into a covered tank and the audience oohed and aahed as the critter swam around for several minutes before the next guest came out.

This wasn't new tech when "The Abyss" came out.

Re:They say no ozone risk

[bassinskeet]

I dont mean to be rude or anything but its not the hydrogen-fluorine-carbon compounds that are bad for the ozone layer. The chlorine-fluorine-carbon compounds are. The reason we are using hydrogen-fluorien-carbon compounds with our non-industrial (not sure if they still use CFC's in industries) is because the chlorine reacts with the O3 and the hydrogen doesnt. Now i may be wrong because i learned it from my thermo prof earlier this year.

Doesn't look promising for cooling.

[Ungrounded Lightning]

If you put it deep enough in the fluid, the bubbles will condense on the way up.

However the shockwaves from their formation and collapse (cavitation) could cause physical damage to the chip packaging, especially where conductors penetrate it. If the chip package isn't designed for it, total immersion is proably out. Back to liquid-cooled clampons. (In which case, why not use water, which has extremely high specific and vaporization heats?)

If the heat of vaporization is anything reasonable, this should work quite well to remove heat from your chip--the fluid changing to a gas absorbs a bunch of heat,

But the heat of vaporization is extremely low compared to water - by a factor of 25! (That's why it can be "stored as a liquid and used as a gas" - the small amount of heat in the air causes a spary to immediately evaporate).

Specific heat wasn't stated - but with such a low heat of vaporization it is also probably low and/or doesn't matter. You're going to have to circulate this stuff REALLY FAST to get usable cooling.

Note that its use as fire suppression is not relevant to its use as cooling. Though this stuff DOES suppress fires by cooling (unlike halon, which interferes with the chemical reactions), fire suppression is a one-pass rather than multi-pass function. So the cooling can be accomplished by breaking up the molecule - using the heat of formation, in addition ot the the specific or vaproization heats, to cool the fuel. I doubt that you want to be continuously consuming your coolant and disposing of the resulting fluorinated alkyl radicals in your home system.

Also, I'm concerned about the toxicity.

This is being sold as a fire suppressant. Fires, and their combustion products, are SO toxic that a suppression system chemical can be quite hellish and still be a drastic improvement. But long-term exposure as an alternative to non-exposure is a far different can of worms.

One document touts that the LD50 (concentration that kills 50% of those exposed) and cardiac sensitization NOAEL (no observable effects level) - both ACCUTE (immediate) poisoning measures - are both "over 10% v/v". But another document, touting its rapid vaporization, point out that the equilibrium vapor pressur in air is four times that: 40% (nearly half the air replaced by vapor). And given how easily this stuff vaporizes, it can approach that damned quickly. So dumping warm coolant might quickly displace nearly half the air with this stuff's vapor and put you in jepoardy - of suffocation if nothing else. Not a problem if it's putting out a fire - BIG problem if it's not.

With that high vapor pressure and low heat of vaporization, exposure would tend to be very high during handling or in the presense of even a tiny leak. So if there are even small long-term toxic effects you'd want to avoid having this where it could result in repeated and prolonged contact.

Re:not an ozone killer

[Mark of THE CITY]

In the chemistry of ozone depletion, an O-X bond is formed, where X is a halogen. Stratospheric UV breaks this bond for X = Cl or X = Br, allowing one atom halogen to destroy many ozone molecules (catalytic destruction). But, stratospheric UV can't break the O-F bond. So one F atom destroys one ozone molecule only.

don't be denied

[zptdooda]

"I seem to remember hearing..."

Maybe this glossary [cray.com] is where the person who told you read it from. Under PFIB it says:

"Perfluoroisobutylene. A toxic, colorless, odorless gas that can be produced when Fluorinert liquid thermally decomposes when exposed to open flames, glowing electric heating elements, electric arcs, or temperatures above 200 degrees Celsius."

NOT NEW!! This is not new I repeat Not New

[tyrione]

Being a Mechanical Engineering by training I used this technology back in early 1990s while doing my undergraduate degree at Washington State University.

It is expensive as hell (at the time it was expensive).

It is by no means a new break through, unless they are considering the barrier of entry being no longer cost prohibitive as a break through.

Re:Hasn't this been done before?

[g-san]

You are not crazy, I saw the same show, so this is not "an amazing new substance." I also recall they were able to do some kind of component fault checking with that liquid too. They dunked a PCB into a tub of this stuff and a small stream of bubbles rose from some failed component. Perhaps that component was excessively hot or something and that was the juice boiling on it.

And I disagree with my co-replyer about coming out wet or dry. If you put something in liquid, it will come out wet. If you put something in sand, it will come out sandy. There will always be pockets that will trap some of this substance. Even liquid mercury, which doesn't seem to get things wet, would find some little nook(s) to get stuck in.

Nuclear Reactors do it

[MikeMo]

Some reactors (namely, Boiling Water reactors) run right at the boiling point. They use nucleate boiling at the surface of the fuel rod to break up a laminate layer that tends to insulate the rod from the rest of the water. In other words, the turbulance caused by the boiling increases the heat transfer rate.

Re:"Water"-cooling

[Laur]

Here's a link to the more detailed [cti.org] explanation of cooling towers at the site you linked to. The "closed circuit" cooling tower consists of two circuits, one of which is closed, the other which is open and is evaporated to the atmosphere. The open evaporation circuit is what is responsible for the cooling. The "cooling tower" method of cooling relies on evaporating a liquid and exhausting it to atmosphere. The grandparent described a closed system where the working fluid was evaporated then later condensed. This is not a cooling tower design, since there is no open component exhausting to atmosphere. BTW, a simple example of a residential cooling tower type device is an evaporative (or swamp) cooler of the type frequently used in hot, dry locations such as Arizona (where I used to live). It works by blowing air over pads soaked with water. The water evaporates, cooling the air, which is then used to cool the house. In this case the "working fluid" is actually the air, not the water, so it is not a straight cooling tower design, but it is very similar.

Ah. No they don't.

[Moderation abuser]

"Fire suppression systems such as those that use Halon (which was outlawed in the '90s due to its ozone-destroying side-effects) put out fires by displacing oxygen with some other gas."

Nope. Halon systems work by absorbing free radicals in the fire. It literally interferes with the chemical processes required to sustain burning. The same reason they are so dangerous to the ozone layer. It's also the reason the newer gas based fire suppressants aren't nearly as effective.

Free radicals are also the reason pre-burned wood can be restarted burning again so easily, and why burned toast is more likely to give you bowel cancer than lightly tanned toast.

Special case

[DarkMan]

Nuclear reactors have a lot of design time to make sure they work. They're also made to exacting tolerances - thus things like the surface roughness are precisly known and controlled.

More importantly, a boiling water reactor uses the water as a moderator. When as a gas, it's much less effective as a moderator than as a liquid. This operates as a feedback system (too much heat generated - water boils - reaction rate slows - system cools), which is critical to the design here. The water would be more efficent at cooling, if the system was run at a lower temperature. However, the system of reactor - turbine - generator is more efficent as a whole when the water is run near it's boiling point (because the heat exchanging systems work more efficently with a greater temperature differenctial).

So, yes, it is used in those cases - but that's not the most efficent method of using the water _as a coolant_. Within a microprocessor, you have no feedback loop to reduce heat production when the temperature peaks the boiling point [0], and no desire to maximise the running temperature.

Personally, I'll stick with water for electronics cooling.

Re:"Water"-cooling

[goat_attack]

According to the Material Safety Datasheet [mmm.com], flowinert only becomes hazardous if heated above 200 degrees celsius. I wouldn't worry about it.

Incidentally, you can drink the stuff!

My observations on this...

[chadjg]

I was a small time firefighter for awhile, and we trained to deal with this stuff all the time.

First off, you can put a fire out by using water to cover all the surfaces and deprive it of oxygen. One one fire the gire started in a basement room that was closed on all sides. We didn't get there fast enough to snuff it out at the point of origin. But the fire damned sure went out when we pumped the basement full. That's not the goal, but it works, guaranteed.

The ideal way of dealing with ordinary house fires is to get there fast enough so it's confined to one room. You advance a hoste team a bit into the room, set the nozzle to a 30 degree fog pattern and move thestream in a clockwise pattern thru the seat of the fire, up to the ceiling and back down. A few sweeps like that and a small fire will be out and you can get to work. At no time is the fire actually "drowned."

If the room is already mostly engulfed, you just crack the door, pump a bunch of fog in, and let your old friend vapor phase cooling suck the heat out of the fire. The only downer is that anybody in there is gonna cook for sure.

In our training burns we would start a fire in the tower, let it build up, and then run the hose team in. The boundary between smoke and clear air is actually quite distinct, i'd say no more than a foot high. When you cut loose with the water everything gets dak fast, the layer drops down, and life starts to suck. It does give ou confidence in your gear though. You have to experience it if you get the chance.

Theoretically you can put out a room fire without causing any water damage by putting in just the right amount of a fog stream into the room and letting all the water be vaporized. But fire fighting isn't ballet, and I've never seen it happen. Usually water damage is pretty bad.

One effect that can't be ignored is the mechanical force of a stream of water coming out of a hose. It can and will tear stuff up. If you spread out the stuff that is burning, stuff gets cooler and is easier to deal with. A nice straight bore nozzle hooked up to a good size pump can and will tear thru roofs without a problem. You absolutely have to get a hold of one of these things at least once in your life :)

This is so not my area, but Metal fires, Class D in the U.S., are only fought with powder extinguishers. Any extinguisher that isn't marked as a Class D is useless and a health hazard. One of the main reason you don't spray water onto a Class D fire is that you tend to get violent and explosive spalling. Life will start to suck in a big way if a moron tries that. It's a specialty area and any shop that workes with these metals, zirconium, and a bunch of others should put bucks into their training and safety gear. It's not to be messed with by amateurs.

Re:Fluorinert

[anethema]

Lets not forget Mineral Oil. This is available at any drugstore, its completely inert, wont harm the environement, wont harm electronics, etc. Works great for immersion cooling. I'm not sure about it's heat transfer propreties, but I sumberged an old pentium for fun. Just left the drives out (hard drives are NOT sealed incase someone didn't know) and the power supply. Changed the cpu fan for something a bit stronger, and put the whole thing in a glass box with some bubbles. Looked very cute, ran decently well. I pumped all the fluid through a small radiator so it wouldnt get too hot. Put some LED's in there..looked nice.

Tech TV did this over a year ago

[tokabola]

They used the Flourinert from 3M (link in another post). Drives are NOT submersed, only the Mobo, CPU and cards. Since it's the CPU, GPU, chipset and memory that really need the extra cooling when overclocking anyway that's fine.
The liquid Tech TV used cost over $900 US per gallon, so Saphire is just a cheaper version of the same basic thing. It's chemically inert (won't cause corrosion), non conductive (won't cause short circuits), and non toxic (fish can live in it if you add a standard aquarium air pump). Overclockers.com also has articles on submersion cooling.
I'm glad to see this, the only thing that stopped me from building an E-quarium (complete with fake swimming fish (no fish poop on my Mobo, thank you!)) was the price, since I calculated it would take three gallons to fill a recirculating system.

Tommy

Re:"Water"-cooling

[Anonymous Coward]

So if your fire cracks water, then burn's the resulting gasses to re-form the water, it's just gotten a little cooler, not hotter.

That's true for fire involving hydrogen atoms. However, regarding the metal-burning-in-water mentioned by the previous comments, sticking the metal atom onto the hydroxide group releases more energy than prying off the proton. These things really do burn underwater. Metallic sodium likes hydroxide so much it ignites spontaneously, with great vigor. ("Great vigor" being chemist-speak for "BANG!")

Some metals, like magnesium, can even burn in carbon dioxide. Even in solid form--stick magnesium inside a chunk of dry ice and it keeps on burning. Care is needed to extinguish burning metal.

Why not just immerse in REGULAR water?

[BigBlockMopar]

how useful would it still be for cooling purposes if it were a gas? Potentially very useful depending on the properties of that gas.

Of course!

More importantly, though, if the "water" is boiling because of the heat of your motherboard, it's undergoing a phase change - while it does that, it will consume all available heat to continue the phase change rather than elevate the temperature.

A pot of boiling water will never get over 100C until after all the water has boiled off (or if you increase the pressure, ie. a pressure cooker or a steam engine - PV = nRT!). Likewise, this will never let the processor get above 50C until all the coolant has boiled off. But if you capture the vapor, condense it, and drip it back into the computer's enclosure, you've got a closed system which is good indefinitely. I would worry, however, that if this stuff doesn't "wet", it probably has a lot of surface tension - so the "water" to processor interface won't be as tight as it would be with water, and therefore there might be a little more localized heating effects, similar to water droplets flying across a hot skillet. On the other hand, I'm sure the liquid, being capable of convective flow and in direct contact with the processor, will probably couple heat at least as well as a conventional heat sink. We should also look up the specific heat of this stuff. (Too lazy, didn't check to see whether it was in any of the cited links.)

Personally, I doubt you'd actually maintain the entire vessel at the temperature of the hottest component (the processor) - convective flow within the enclosure will move the hot "water" to the outsides of the container, where the surface area (thousands of times greater than the surface area of the processor) will couple away the heat to the atmosphere.

But why can't you do this with regular water? Submerge the motherboard and cards only - not the drives or the power supply. The thermal transfer grease isn't water soluble, so I don't think you'll make it into a conductive ionic solution. Voltages from pin to pin are pretty low, and pure water is a good insulator - the only problem is getting pure enough water, and keeping it pure enough. Corrosion will also not be a problem, again if the water is pure, the motherboard is continually submerged (preferably with a small surface area to the air so that less oxygen dissolves in it), and connectors are tin/nickel/gold plated - as most of them are. Wash the motherboard/cards/cables in distilled water before putting them into the bath, to make sure that you don't take any ionic contaminants (salts, etc. in dust, fuzzies around old CMOS batteries, manufacturing chemical remnants, little bits of leakage from electrolytic capacitors) in with you.

Components? Modern components are usually sealed anyway - the last step of manufacturing is removing the soldering flux, and that's usually done in what is, essentially, a dishwasher. They're not actually rated for immersion, but most of them do take a good spraying. I'd take out PC-board mounted piezo speakers, but offhand, I think that's the only part that would really have a problem with it.

I think I'd try this with an old computer before doing it with my real one. I seem to have an old 486DX-33 with 30-pin SIMMs and 16-bit ISA slots only... it's been begging for a job. I'll check out retail distilled water on my megaohm meter first.

Re:Bad idea.

[rthille]

Just because the coolant is boiling doesn't mean the cooling properties break down, they are just different.
The droplet of water example is pretty silly, since little droplets of water wouldn't cool the pan much even if they weren't boiling.
Here's an example that shows that even boiling water cools just fine. Take a sheet of notebook paper and hold it over a gas stove. Watch it burst into flames. Now fold another sheet of notebook paper until it works as a paper cup. Fill the paper cup with water, put directly over the flame of the gas stove. Wait for water to boil, add tea bag and enjoy.
Google Search for 'water boil paper cup' [google.com]

Credulity Alert

[blair1q]

From the article: "The chemical has all the firefighting properties of water..."

Except one. It doesn't wet. It will slide right off anything it touches, allowing the fire back onto it.

We also don't know what its evaporative cooling properties are. Someone might, but we don't. The misting of water in a burning room cools gases and reduces flashing probabilities.

The smothering property is nice, but it doesn't have all the firefighting properties of water.

But then, it has firefighting properties water doesn't have. Water, for instance, will cause electrical fires, and electrical explosions if the voltage of the electrical system is particularly high (first it electrolyzes to hydrogen and oxygen, then it recombines explosively to become water again).

Re:Why not just immerse in REGULAR water?

[RedWizzard]

A pot of boiling water will never get over 100C until after all the water has boiled off (or if you increase the pressure, ie. a pressure cooker or a steam engine - PV = nRT!). Likewise, this will never let the processor get above 50C until all the coolant has boiled off.

Not quite. The water in a pot of boiling water will never get over approximately 100C, the pot however can be higher than that. It all depends on the efficiency of the heat transfer from the element to the pot to the water. You think an element on a stove suddenly drops to 100C when the water in the pot starts boiling? So the phase change in this Sapphire-based system won't limit the processor to 50C. Infact once the stuff starts boiling the system will probably lose efficiency. That's why most cooling systems work on the principle of circulating coolant rather than phase changes.

Re:question about not being wet

[aXis100]

Things 'wet' due to very small forces between molecules. For instance, water molecules are more attracted to paper than to itself, so paper gets wet. Water molecules are not attracted to grease/oil, so they dont mix.

Same thing here - basically the liquid is more attracted to itself than other objects, so it basically stays in it's own droplets.

That's about as simple as it gets.

Re:Evaporation...

[Rich0]

CO2 is not dangerous at all for any reason other than it displaces the oxygen. that is it.

Not true. Suppose I set up a room which has a normal atmosphere, except the N2 concentration has been reduced by 10%, and Argon was added in its place. It probably would have little to no effect, since argon is not involved in any metabolic reactions.

Now suppose I had a room where the N2 concentration was reduced by 10%, but CO2 was added in its place. That would probably kill you.

Why?

Simple - in order to get rid of CO2 built up in the body, you need a lower partial pressure of the stuff in the atmosphere. If you raise the atomspheric pressure of CO2, the amount in the tissue will also rise.

Now, take the chemical reaction:
Sugar + O2 -> H2O + CO2 + energy

As long as O2 is plentiful and CO2 is rare, this reaction moves forward quickly, generating energy for the body to use.

If CO2 builds up, then this reaction will produce less energy, and you will die.

A little thermo (it has been a few years - I'm sure somebody in freshman chem can fix any errors):

Delta-G = Delta-G-0 + RT ln Q

Q = [H2O][CO2] / [sugar][O2]
(Ok, I'm neglecting stoichiometry, but this is fine to show the trend).

If the concentration of CO2 increases, then the value of Q increases, and therefore Delta-G increases. The more negative Delta-G is, the more energy is produced by the reaction which is useful for work (such as staying alive). An increase in Delta-G means less energy for work. When Delta-G hits 0 you're at equilibrium (and your body temperature will hit room temperature eventually - not a good thing). Of course, you're effectively dead long before you actually hit equilibrium.

Note that in normal live [CO2] is very low - so it doesn't matter how much water is around.

Oh yeah - I am a biochemist... I don't have practical experience with this, so I don't know how much it takes, but too much CO2 will certainly kill you even if O2 is at 20%.

This whole bit is the reason that submarines have scrubbers...

Re:Fluorinert

[khallow]

Please, if you don't know anything about the topic, don't clutter up slashdot with meaningless speculation. That's my job.

From here [arizona.edu]:

Patients Breathing Liquid in UMC Intensive Care Unit

By Kevin Rademacher

Like a scene from a science-fiction movie, some of the sickest at University Medical Center are breathing fluid as a critical life-saving treatment.

Steven B. Johnson, MD, associate professor of surgery at the University of Arizona College of Medicine, and Steven R. Knoper, assistant research professor with the College of Medicine, are leading a study examining liquid ventilation, a new treatment that has produced impressive results.

The liquid is administered to patients suffering from severe acute respiratory distress syndrome (ARDS) and breathing with the aid of mechanical ventilation. The liquid ventilation therapy involves trickling the fluid, LiquiVent®, into the patient's lungs through the endotracheal tube.

The fluid _ a clear, colorless, oily liquid that looks and flows like water but is twice as dense _ carries oxygen and promotes respiratory gas exchange while opening up the lungs. The dense fluid also serves to wash out the ailing lungs, assisting in the removal of debris and other contaminants.

A picture of a 1960's mouse in a beaker too.