Vacuum: effects on cooling?

[Crazy Jayhawk]

This was suggested by a friend of mine. What would happen if the interior components of the computer were placed in a vacuum? We're assuming that there is proper sealing around expansion slots and that there are no air bubbles or other defects that would cause components to explode in low pressure.

On the one hand, the ambient temperature of a vacuum is something around 30 degrees above absolute zero. On the other hand, there's nothing in a vacuum to dissipate heat.

What do you think would happen to a running computer in this environment?

[nihili]

There is no such thing as the normal temperature of a vacuum. A complete vacuum has no temperature. Anything short of a complete vacuum has a temperature dependent on the energy put into it.

In short, the computer would fry, big time.

nihili

[r0ckstarbob]

so what about watercooling in a vacuum?


thinkin thinkin thinkin.... aw crap... there goes the gerble again...

[m1066ad]

If you ran the water coming out of the water block through a volume of reduced pressure, then ran it through a heat exchanger, then compressed it, and ran it back through the water block...if you did all that, then replaced the water with, say freon, or ammonia...

[IFMU]

Originally posted by nihili
There is no such thing as the normal temperature of a vacuum. A complete vacuum has no temperature. Anything short of a complete vacuum has a temperature dependent on the energy put into it.

In short, the computer would fry, big time.

nihili

Ok you lost me there... how does a complete vacum have no temp? and let alone how can you say that its a complete vacum? Im imagining theres something I dont know, so please inform me! I need a few new brain wrinkles...

[r0ckstarbob]

Originally posted by nihili
There is no such thing as the normal temperature of a vacuum. A complete vacuum has no temperature. Anything short of a complete vacuum has a temperature dependent on the energy put into it.

In short, the computer would fry, big time.

nihili

okay, lets phrase it this way.

you've got a brand new ice box, never been turned on, and it has an air-tight seal. this icebox gets infinately cold

now... you close the door, plug it in and turn it on. as the air gets colder you begin to create a vacuum.

if i'm to understand you correctly, and using this example, you're saying that theres going to be a point in this vacuum creating process where the temperature is going to become null?

i know temperature cannot traverse a vacuum. but if the temperature is being created inside the vacuum, what then?

[r0ckstarbob]

Originally posted by m1066ad
If you ran the water coming out of the water block through a volume of reduced pressure, then ran it through a heat exchanger, then compressed it, and ran it back through the water block...if you did all that, then replaced the water with, say freon, or ammonia...

*chuckle*

smart ass ;)

i think i like you already... :D

[m1066ad]

"Temperature" is a property of matter. Vacuum is the abscense of matter.(More properly, the attenuation of matter). The only thing you can measure about vacuum is pressure.(Unless maybe you want to really get technical, and measure the quantum energy level)
As for the cooling question, the main mechanisms of heat transfer for water or air cooling, are conduction, and convection. Radiation plays a very minor role, in such a system. In a vacuum, on the other hand, radiation would be the only mechanism by which heat could be dissipated.
To quote Nihili, "Your computer would fry".

[r0ckstarbob]

okay, well i'm curious then... this might have direct impact on that project i've been working on - the Core Project.

don't know if you remember (or ever checked out that link) but my question is,

my core is about to go from room temperature to -30C with an air tight seal, and it will happen in approximately 20 minutes from the time i plug it into the wall.

will the resulting vacuum be a problem?

[The Overclocker]

ok, people are getting too compilcated,

space is a vacume
the only way heat reaches stuff in space is through radiation

that is why astronoughts have silver or white spaces sutes, to relflect heat

[SavageHenry]

Originally posted by r0ckstarbob
okay, well i'm curious then... this might have direct impact on that project i've been working on - the Core Project.

don't know if you remember (or ever checked out that link) but my question is, my core is about to go from room temperature to -30C with an air tight seal, and it will happen in approximately 20 minutes from the time i plug it into the wall.

will the resulting vacuum be a problem?

It shouldn't be, as long as you choose a sealant (o-ring, gasket, etc) that doesn't become brittle at -30C . . .

At low temperatures and pressures, air behaves similarly to an ideal gas, so you should be able to calculate how much of a pressure drop you're going to have for a given temp drop, and choose a seal that will handle that much pressure.

[r0ckstarbob]

cool. thanks for the tip on the gasket. thats definately good info to know. was curious as to how this vacuum i'm about to create is going to affect the heat transfer capabilities of my system and if i'll have to "break the seal" so to speak just at peak cold time (just for a quick second) to prevent that vacuum from affecting my system negatively.

[SavageHenry]

Originally posted by r0ckstarbob
cool. thanks for the tip on the gasket. thats definately good info to know. was curious as to how this vacuum i'm about to create is going to affect the heat transfer capabilities of my system and if i'll have to "break the seal" so to speak just at peak cold time (just for a quick second) to prevent that vacuum from affecting my system negatively.

Nah, I doubt you'd see any more negative pressure than you'd see if you set up a case full of exhaust fans . . .

[BubbaJoeLouis]

Okee dokee here goes BJL again, a rantin' and a ravin'...

What is heat?

Heat is the motion of particles. Cold is the lack of motion of particles.

Your processor is basically one buttload of electrons (small parts of particles) moving like crazy. That which is moving that doesn't process 0s and 1s is heat.

We stick copper against our processors because the particles in copper are easily excitable. Heat moves easily into it. Water get excited pretty easy as well, and is a little more liquid than copper at 50*C.

Conductors are easily excitable, heat conductors are given to particle motion, and electrical conductors are given to electron motion.

Insulators are not easily excitable. Still air is a good insulator, there aren't too many particles in it, at least not compared to copper. You move the air quickly, the air compresses and increases the number of particles.

A Thermos is an insulator, a glass case with most of the particles removed, creating a vaccuum.

A vaccuum is the absense of particles. Of course, a perfect vaccuum is impossible, even space has a particle or two every couple square miles.

Spacepeople wear suits to remove the particle motion generated by the living body, otherwise their blood would boil. How these work would probably be benificial to our studies.

Now apply this stuff to computers...

A vaccuum inside a case could be the best possible thing, provided you remove the heat properly. If the whole case were a vaccuum, every transistor would melt down.

A vaccuum around a Peltier device would stop any water condensation and freezing. Most Peltier device manufacturers recommend vaccuums around their devices.

Wow, I think if we all put our heads together, we could work for NASA in NO time.

BJL;)

Why yes, I AM a rocket scientist.

[r0ckstarbob]

Originally posted by BubbaJoeLouis
A vaccuum inside a case could be the best possible thing, provided you remove the heat properly. If the whole case were a vaccuum, every transistor would melt down.

i apologize for my denseness on this topic but...

the above statement seems to be a bit contradictory and is a little confusing. so a vacuum is a good thing or a bad thing?

if you want a better idea of what this is for, check the sig.

Crazy Jayhawk... my apologies if i've preempted your place in this thread with my questions on this topic...

-RSB

[m1066ad]

That's because it is contradictory.(Somewhere a physics teacher is crying) Cold does not "make a vacuum". Making a volume of air colder will reduce the pressure inside the volume, and adding heat will do the opposite.

[r0ckstarbob]

okay, there seem to be alot of partial and/or contradictory answers here. lets start from the beginning.

we'll make it simple.

when overclocking our machines, a vacuum is.....

good... |_|
or
bad ... |_|

please check the appropriate freakin box. keep in mind the perspective of this topic - lets chuck the "theory" of infinate vacuum and space and keep our focus on earth and what we're likely to run into while OCing our machines.

shoving your box in a freezer and turning it on is going to create a vacuum. is this good or bad?

now that that part of the question is out of the way, could you please explain why?

i'm not trying to be impatient, but some straight answers with directly applicable reference points seem to be sorely lacking here. they seem to be getting tangled with the spacemen and einsteins law of relativity over a guinness and the price of tea in china.

;)

[r0ckstarbob]

apparently the debate is between a rocket scientist and a TEC engineer. should be interesting...

[m1066ad]

Sticking your box in a freezer will make it run much cooler, lol. There, was that simple, or not? The temperatures created inside a freezer will result in a negligable pressure differential, any "vacuum effect" will be, for practical purposes, immeasurable.:cool:

[r0ckstarbob]

heh

wurd up brotha. thank you. i figured as much but ya know... never hurts to check.

you da man sam. :D

RSB

[BubbaJoeLouis]

Sorry for that confusing line... it was poorly written.

I was hoping you would understand vaccuums enough to decide for yourself.

A vaccuum COULD be the best thing because then you have complete control over your environment, provided you remove the heat properly, just like a spacesuit. And the heat generated by your CPU could not heat up your RAM.

A vaccuum in the entire case would, in reality, be BAD. You would have to put a heat sink and some waterflow on EVERY piece of electronics, as well as the hard drives and power supply. If you overlooked a transistor, and it wasn't able to sink its heat through the motherboard, or case material, it would probably fry.

A vaccuum around your waterblock(s) would be VERY VERY GOOD. That way if you acheived temps below the dew point, you would not get condensation/frost buildup. Because there would be very few water vapor particles to freeze.

BJL;)

Give a man a fish, and he will eat for a day. Give him a hook and he can have a really groovy earring.

[SavageHenry]

Originally posted by r0ckstarbob
okay, there seem to be alot of partial and/or contradictory answers here. lets start from the beginning.

we'll make it simple.

when overclocking our machines, a vacuum is.....

good... |_|
or
bad ... |_|

please check the appropriate freakin box. keep in mind the perspective of this topic - lets chuck the "theory" of infinate vacuum and space and keep our focus on earth and what we're likely to run into while OCing our machines.

shoving your box in a freezer and turning it on is going to create a vacuum. is this good or bad?

now that that part of the question is out of the way, could you please explain why?


Shoving your box into a freezer won't create a vacuum, it will create a negative pressure differential between the box and the air outside . . .

Even if it did create a vacuum, it would be a bad thing . . . even in a watercooled system, a lot of your components (sound card, NIC, HDDs, CD, etc) are cooled by convection (in this case moving air). Without the convective cooling, you'd have to actively cool EVERYTHING that generates heat, or risk overheating something . . .

[Intraveinous]

Originally posted by r0ckstarbob
they seem to be getting tangled with the spacemen and einsteins law of relativity over a guinness and the price of tea in china.;)

Guinness = Good
Tea in China = $0.12/cup if purchased in 1/4 kilo increments

Therefore, the price of Guinness in Ireland is 2 times the coefficient of pi divided by the temperature of a frying egg at absolute zero, converted to newtons, not of work, but instead the fig variety.

It all makes sense, so long as you have the 6 pints of Guinness first.
heh...
Sorry, all this stuff was making my head hurt... Yes, please, Vacuum in a computer = good or bad when overclocking and examples, scientific evidence to back it up... Thank You!
John

[nihili]

Vacuums and Temperature101

Caveat: What follows is a long winded and idealized primer on applied ideal gas theory. If you don’t want to read something basic, don’t read this. If you feel compelled to point out that air isn’t a truly ideal gas, well go ahead if you must, but it doesn’t really change anything important at the basic level.

The relationship between the pressure temperature and volume of a gas is given by the formula
PV=nRT where n is a measure of the quantity of the gas and R is a constant. The important thing is that P, V, and T (and n) vary in relation to each other. So if you hold one of them constant and make a second one change, you’ll cause a change the third. Here are some examples:

Filled Balloon
Take a filled balloon and put it in the freezer. The air in the balloon gets colder, but stays at the same pressure and quantity, so the volume has to decrease. Try it, your balloon will shrink.

Hot air Balloon
Here we heat up air while keeping the volume constant. Heating the air initially causes the pressure to rise which then forces air out the bottom of the balloon thus decreasing the quantity of air in the balloon. The air in the balloon now has a lower pressure (is less dense) than the air outside the balloon, so the balloon rises until the pressure equalizes with the outside air.

Notice that in these cases we changed things by adding or subtracting heat from the gas. An interesting set of cases resulting from the Ideal Gas Law stated above are known as adiabatic processes. In these processes the temperature of a gas is changed without adding or subtracting any heat from the system.

Closed Piston (adiabatic)
If you have a piston with a constant quantity of gas in it, then you can change the temperature of the gas without adding or subtracting heat from the chamber. If you compress the cylinder you increase the pressure of the gas and decrease it’s volume. But the pressure increases faster than the volume decreases so the temperature has to increase. If you expand the cylinder, the opposite happens; the volume increases, the pressure and temperature decrease.

Closed box (non-adiabatic)
In general decreasing pressure decreases temperature. That’s what we saw in the piston example. Well if you could decrease the pressure while also subtracting heat from the system, you could cool things down in a big hurry. It turns out to be very easy to do that. Get a sealed box and hook a vacuum pump up to it. As you take air out of the box you decrease the pressure while keeping the volume constant, so the temperature drops. But also the air that you take out contains heat, so you’re subtracting heat from the box and the temperature drops even faster.

Constant volume with a decreasing pressure and decreasing quantity of gas leads to rapidly falling temperatures, sounds like the holy grail of cooling. But there’s a catch. After you’ve taken as much air as you can from the box, the temperature stops dropping. Unless you’re box is a perfect thermal insulator (t’ain’t no such thing) it’s internal temperature will start creeping up as it absorbs heat from the environment until it reaches ambient temperature. Computer cases btw are lousy thermal insulators so it will “creep” up really fast. Furthermore, as soon as you turn on your computer you create a heat source inside, so it creeps up even faster.

The Moral of the Story
Creating a vacuum in your computer will decrease you temperatures for a very short while. After that, the temperature will rise fairly quickly. In part two I’ll explain why the temps will climb high enough to fry your chip.

nihili

[m1066ad]

Well, yes. What Nihili said^
I agree, of course(have to be an idjit, not to), I was just trying to answer RSB's Q very basically, with the info I thought he wanted. A refrigerator, or freezer, is designed to move heat from the inside of the enclosure, to the outside. As long as the refrigeration or freezer unit is designed to remove more heat than the computer can make, putting a computer totally inside one would do the trick. I believe that was the gist of the question, and as far as I know, it'd work. Am I missing something, here? Aside from the practical matter, that it's one hell of a lot of trouble to go to, for an unknown amount of improvement in performance, that is...:)

[Rafterman223]

bubbajoelouis is absolutely positivelt right

[SavageHenry]

very well said nihili

[nihili]

Vacuums and Temperature 102
Or How to Make a Keychain

Ok, let’s think about a typical computer in idealized terms with respect to cooling. Basically it’s a container with a fixed volume and an internal heat source. If all the heat produced by the cpu stayed inside the case, the temps would climb indefinitely high until the whole thing melted or exploded. So the goal of cooling is to find some way to move the heat away from the cpu and outside the case. So we want to get the heat from point A (the cpu) to point B (outside the case)

There are basically three ways to move heat from point A to point B. You can carry it, transfer it, or beam it. Carrying it is the most efficient, then transferring it, then beaming it. Here’s what I mean by each of them.

Carrying
If you don’t like the heat, move the stove out of the kitchen. Basically if you want to move heat, find something hot and move it. All the heat goes right along with it. You can move massive amounts of heat very quickly this way. This is what your case fans do. They take hot air from inside the case and move it to the outside. Voila! Instant temperature drop. The more heat the thing you carry has in it, the more heat you move. That’s one of the advantages of water cooling. Water carries more heat than air does, so you don’t have to move as much of it to get the same reduction in heat.

Transfering
If you have something hot and you want to cool it down but don’t want to move it, put something cold next to it. Some of the heat will go over to the cold thing thus reducing the temperature of the hot thing. This is the principle behind a heat sink. The CPU is hot, so we put a sink on it and some of the heat goes to the sink. This reduces the temperature of the CPU. The problem is that if the hot thing is actually producing heat (as a CPU does), it will eventually make the cold thing hot too. So then you need another cold thing, which in turn will eventually get hot, etc. Also, transferring can only move heat for relatively short distance. So transferring is generally used in conjunction with carrying. Once the cold thing gets hot, you carry it away and put a new cold thing next to the hot thing. This is why we blow air across heatsinks. The heatsink makes the air around it hot, the fan moves the hot air away and replaces it with cold air. This cools the heatsink which in turn can cool the CPU some more. Different materials are able to transfer heat at different rates. Water is better than air, copper is better than aluminum. This is why watercooling and copper heatsinks have become popular.

Beaming
Also know as radiation. In this method you change some of the heat into electromagnetic radiation (infra-red light for example). The radiation can actually move across great distances. When the radiation is absorbed by an object, it changes back to heat. The problem with using this method for computers is that you have to have some way of changing heat into electromagnetic radiation. The easy way to do that is to make something so hot that it glows. This is great if we’re talking the sun or the elements on your stove, but not so great if we’re talking your CPU. So for computers we’re limited to transferring and carrying.

Now lets get back to vacuums. If you take all the air out of your case, then you can’t use it to carry heat out of your case. You could of course compensate by using water cooling. But since every electrical component in your computer produces heat, you’d have to water cool your entire motherboard, all the drives, and all your cards, not to mention the power supply. While this would potentially keep your temps nice and cool, it’s pretty difficult to do.

Here’s what would happen if you turned your computer into a vacuum.

Basically you have a sealed box with a heat source in it, but nothing to conduct heat away from the source. The source is going to keep producing heat as long as it can. But with no way to move the heat away from the source, it’s temperature will just keep rising until it starts glowing brightly enough to radiate the heat away at the same rate that it produces it. Guess what, your chip will fry long before you get to that stage. And if you decide to water cool the cpu, well guess what, the northbridge will do the same thing, it will just take longer. Gonna water cool the northbridge? Now the ram will heat until it fries. Water cool ram? Now it will be the south bridge. Etc.

In terms of using a sealed box for a computer you’re far better off to use a high pressure system than a low pressure one. Of course course the best thing would be to submerse your entire system in a nonconductive liquid, but that’s a topic for another post.

nihili

[nihili]

Originally posted by r0ckstarbob


okay, lets phrase it this way.

you've got a brand new ice box, never been turned on, and it has an air-tight seal. this icebox gets infinately cold

now... you close the door, plug it in and turn it on. as the air gets colder you begin to create a vacuum.

if i'm to understand you correctly, and using this example, you're saying that theres going to be a point in this vacuum creating process where the temperature is going to become null?

i know temperature cannot traverse a vacuum. but if the temperature is being created inside the vacuum, what then?

I'm saying you'd never have a vacuum, just low pressure. I'm also saying that all the cooling work is being done by the refrigeration unit, not by the pressure decrease. Lowering the temperature is causing the pressure decrease. The pressure decrease isn't causing a reduction in temperature.

nihili

[m1066ad]

Wow. I repeat, wow. That was a thing of beauty, Nihili:)
I wish I could explain things that clearly. :(
*wipes tear from unschooled eye*

[nihili]

Originally posted by r0ckstarbob
okay, well i'm curious then... this might have direct impact on that project i've been working on - the Core Project.

don't know if you remember (or ever checked out that link) but my question is,

my core is about to go from room temperature to -30C with an air tight seal, and it will happen in approximately 20 minutes from the time i plug it into the wall.

will the resulting vacuum be a problem?

The resulting low pressure will make heat convect away from the source at a slower rate. I'm presuming you have a refrigeration unit to produce the temperature drop. That should more than compensate for the slower convection due to pressure.

In this case you're manipulating the temps and getting a side effect of pressure drop. Since you're directly manipulating the temps, you can compensate. The original post was asking about manipulating the pressure as a way causing the temps to drop. That only works for a very short time, then you've got a keychain.

The only way I can think of to effectively lower your temps by manipulating pressure would be to construct a heatsink in the form of an airfoil and then blow tons of air across the top of it. The resulting constant decreasing pressure above the foil should adiabatically decrease temps. I should say that I think this idea is far from practical.

nihili

[nihili]

Originally posted by m1066ad
Wow. I repeat, wow. That was a thing of beauty, Nihili:)
I wish I could explain things that clearly. :(
*wipes tear from unschooled eye*

Thanks, m1066ad, that means an awful lot to me.

nihili

[r0ckstarbob]

nihili

w0W! that was AWESOME. BubbaJoeLewis, m066ad - also very helpful and insightful.

This was one of the questions that i had when designing the Core Project but never got answered sufficiently and i kept forgetting to ask myv65 in my emails. not that it was a BIG concern, but a concern that i felt deserved addressing all the same.

thank you boys for the patience and time that has gone into your replys on this topic. nilihi, your posts are getting cut and pasted word for word directly into my notes on the Core Project in answer to this question (if you don't mind that is).

the moral of this topic? when great minds come together, watch the hell out!

m1066ad - expected performance increases of the Core are predicted at 25-30% better then either Vapochill or Kryotech. and you're right, alot of work to go into. in its current design, not very practical for marketing purposes, though future manifestations should be. it's focus is not to only OC the CPU, but OC the entire FSB too.

'preciate it kids. keep up the good work.

again, i apologize for any impatience i showed and to crazy jayhawk for inadvertantly preempting your place on this thread with my questions.

[dugans]

I like it.
Take this in the right way, please, but this thread is great: it lets me know that I am NOT the only person around that can make just about anything more complicated than needed!:)

I did learn a lot more about vacuum and temps than I knew before (and I already had a very good working knowledge of the basics) and all the posts were very informative and well written.

Thank you all!

[anthraxjack]

when is your next shuttle launch nihl?

[ZeroKelvin]

Hey I don't mean to get of the subject. This stuff is way over my head. I was wondering.....what if DOG spelled CAT. Think about it!

[Caffinehog]

OK, in english: A vacuum will give you nothing to carry the heat away. Ever wonder why they use vacuum bottles in thermoses to keep things hot or cold? No heat is transferred.
Water cools better than air. Why? There is more density of matter to carry the heat away in. Water is one of the best fluids for this. Why? Well, I won't go into the scientific why, but its molecular structure allows it to carry more energy than most other fluids.
Sucking out air will make it expand. Does air get colder as it expands? Yes. This is how early refridgerators worked. Modern ones, (such as vapochills,) take this a step further by evaporating a liquid. But if you get rid of all the air, you will have nothing to carry the heat away!

[Caffinehog]

P.S. Heat is a property of how much energy is stored in matter. Temperature is a measure of a medium's ability to release heat to another medium. Water has many vibrational states and bonds into which it can accept energy, as well as intermolecular hydrogen bonds. Metals have only weak bonds, and air has very little, along with its low density. Therefore, water holds a lot of heat at a given temperature, metal holds a little, and a little heat will increase the temperature of air a lot. This is why watercooling is the best and heatsinks are necessary as a bare minimum. In a vacuum, you get only radiative cooling... that's giving off light. Sure, there's IR light, which can carry some heat away, but that's a tiny amount. Our sun is at, hmm, if I recall correctly, it's about 10,000C...(don't quote me on that...) but it only reaches a max of about 40C on earth, because its energy is only transferred radiatively. There is convective cooling, where something is heated and then moved away by motion. Air does this. There is also conductive cooling, where heat is transferred from one molecule to an adjacent molecule by contact. Air molecules rarely touch, so they don't do this. Metal and water molecules do touch, so they do this well.

[fletch]

well, other than the fact that the heat couldnt dissipate... ;)

[EBFoxbat]

in a vacume you would have to water cool. The cpu would heat up (even with a heatsink) but the heat could not be transfered to the air, because there is none. A fan would do no good, as all it does is accelerate air molecules.

Then again, with water cooling...how could u cool the water...a radiator wouldn't work...again, no air.

[-=Mr_B=-]

Back to space.. Correct me if im wrong. But dont they use "air cooling" out there?
Is it radiation only or the few particels that is out there ruining the wacum is enought to make a huge cooling diff?

Wondering
A fan of nihill
B!

[EBFoxbat]

What do you need to cool in space ?

[Avatar28]

No, the space shuttle uses radiative cooling. That's why the inside of the shuttle doors have those big black panels on them. It's the cooling mechanism. That's also why the shuttle always flys with the cargo bay doors open.

[EBFoxbat]

It seems you are correct...

Quote from NASA webste: "The payload bay doors are opened shortly after orbit is achieved to allow exposure of the environmental control and life support system radiators for heat rejection of the orbiter's systems. "

Looks like NASA's computers run hot too....

[Caffinehog]

Originally posted by EBFoxbat
in a vacume you would have to water cool. The cpu would heat up (even with a heatsink) but the heat could not be transfered to the air, because there is none. A fan would do no good, as all it does is accelerate air molecules.

Then again, with water cooling...how could u cool the water...a radiator wouldn't work...again, no air.

Yep! And guess what? Even if you could watercool in a vacuum, the OTHER components would be unable to get rid of heat, so everything else on the board would fry!

[EBFoxbat]

Ok...so we make a ZIF socket extender so the CPU is outside of the case....then we can cool it and not worry about condensation.... hmmm... :cry:

[EBFoxbat]

I do suppose...you could put your case in a vacume and have your water tubing leaving the vacume for cooling then returning into the vacume......though i dont see any benifit.... except that you wouldn't ever have any dust...if your vacume worked

[DarkJediSleikas]

Very well stated nihili. The force is strong in you.

Remember that temperature, at least for gases and liquids, is the measure of the average momentum of the molecules. In an ideal vacuum, there are no molecules. If there are no molecules, there can be no momentum. Does this mean that there is no temperature, or that the temperature is absolute zero? I think that it can be interpreted either way.

[Spode]

if there is a complete vacuum, there will be no cooling. Moreso, there will be no air resistance and the fans willblow up.

[EBFoxbat]

First of all... a 12 V fan will not blow up in a vacume....trust me. Second of all, absolute zero is when molecular movement has stopped all together....in a vacume there are no molecules to stop....there is no temperature... there is heat but no temperature. By the way.... a thermometer in space (or a vacume) does not measure the temperature of air.... as there is none....the mercury (or thermistor) actually measures the the movement of the molecules of the thermometer itself...the glass tube or the thermistor cover.... the molecular movement is very close to none in space... regaurding heat....therefore the temperature in space....taken from an earth-based thermometer...would read close to...but not at absolute zero... I wrote a paper on this back in the day.

[Krusty]

I began to lose interest around the end of the first page of this thread, so excuse me if this hasn't been pointed out already...

For those of you relying on air to cool your computers, vacuum=bad, which we all know by now. But this also means high pressure=good! The more cool air molecules you have moving through the hot bits of your computer, the faster the cooling is. This could be accomplished through bigger fans blowing the air faster AND/OR a higher density of air molecules.

Let's say one unit of air (some arbitrary unit) needs to be pushed through your heatsink to cool one unit of heat (arbitrary unit). With a bigger fan, you could push 2 air units through instead of your usual one unit. At a higher pressure, you could squeeze 2 air units into the package of what is usually 1 air unit and achieve better cooling that way.

So, if you are planning on sticking your computer in a freezer to cool it and want to go even further, you could completely seal and reinforce the refrigerator and rig it to use a bike pump to increase the pressure.

Ooh, that would make one helluva front page article! Too bad the increased pressure method could only be used in conjunction with a heat exchanger such as a refrigeration unit. You don't want all that cpu heat building up inside an airtight box with no place to go.

[RoadWarrior]

So to have an ultimate air cooled 'pooter you have to put it in a watercooled, box...... right!

Be enlightening to sink out a motherboard and and actually try running it in a vacuum, I mean, after you replaced all the electrolytics when they popped for the fifth time, and you're wondering why you get this bluey purple glow around some of the thinner traces on the board, and spurious memory errors, due to the thermionically emitted electrons landing where they aren't wanted, yes, a very entertaining, and enlightening experiment.

However, all trivialities aside, I do remember hearing of some sonically tuned heatpipe thing that converts heat to light... ... ... totally forgot what it was called, anyhoo, you could use a hundred of them to cool down your bare orbitting mobo and shine the light at siberia and bill the russians... ... ... ... or something

[EBFoxbat]

thermionically emitted electrons huh? care to explain that.

Heat induced ions that emit electrons? what difference does a vacume have on them? we're not talking a zero-g vacume

[Deadphishy]

Originally posted by The Overclocker
ok, people are getting too compilcated,

space is a vacume
the only way heat reaches stuff in space is through radiation

that is why astronoughts have silver or white spaces sutes, to relflect heat

i don't know if this was said already but space is not a vacume it just has such low pressure we consider it a vacume. thier are countless numbers of hydrogen and nitrogen particals in space, along with all the starrs and planets. they too are matter, and if you say all of space they are just like the atoms in a jar of air thier are spaces between each one. just let you know. oh yea theirs radiaton in space wich is alpha and beta particals, wich are Protons, and electrons, aka matter.

[RoadWarrior]

Originally posted by EBFoxbat
thermionically emitted electrons huh? care to explain that.

Heat induced ions that emit electrons? what difference does a vacume have on them? we're not talking a zero-g vacume

Well some of the thinner traces may get warmer than their ability to dissipate very well since a lot of the passive convective cooling from the mobo backplanes is cut off, so when they get a bit warm they'll get an electron cloud around them. Now normally it would take a high voltage to pull many of them off, but I figure a few would get set flying around by the fields around the switchmode power conversion circuits on the motherboard among other likely sources. Yer basic vacuum tube/valve theory. 1940s vintage radiograms never needed to go orbital to work ;)

All sorts of wierd stuff is gonna happen.

Road Warrior.

[EBFoxbat]

Originally posted by RoadWarrior


Well some of the thinner traces may get warmer than their ability to dissipate very well since a lot of the passive convective cooling from the mobo backplanes is cut off, so when they get a bit warm they'll get an electron cloud around them. Now normally it would take a high voltage to pull many of them off, but I figure a few would get set flying around by the fields around the switchmode power conversion circuits on the motherboard among other likely sources. Yer basic vacuum tube/valve theory. 1940s vintage radiograms never needed to go orbital to work ;)

All sorts of wierd stuff is gonna happen.

Road Warrior.

nothin personal, but i disagree...no problems with electronics in a vacume