Would Dry Ice base cooling systems work?

[zollen]

Just out of curiosity... Would Dry Ice base (solid carbon dioxide) cooling system much more effective and *safe* than water cooling system?

[PrntRhd]

IMHO, I don't think so.
You do not have to get the CPU below room temperature to be effectively cooled.
Dry ice evaporates (sublimation) and the contact point with the CPU die may be problematic to maintain an even contact patch. You would have to have some method of continuously applying more dry ice to the evaporating dry ice block.
You would need enough air changes in the room to not be smothered by CO2 gas. You need to wear protective gear to prevent frostbite from contact with the dry ice.

[mjc]

Add to that...condensation. Unless you are in a completely dry room (0%) humidity, condensation will eventually do you in...remember all the problems the space station had a few months ago? It was caused by condensation from an uninsulated air line feeding cooling air to the computer. The line passes through an area that is not pressurized/insulated from the cold of space...(and the temporary fix for the problem...all purpose gray tape and pages from a 'spare' tech manual...)

[Sylvander]

Even metal can only stand a certain limited temperature range.

Dry ice is so cold it would probably make the metal extremely brittle and liable to break, plus "Thermal Shock" effect.
The effect on everything it came into contact with would probably be very destructive, possibly deadly.


How Dry Ice Blasting Works (http://www.diamonddryiceblasting.com/cleaner.php).

As a hazardous material (http://www.glue.umd.edu/~choi/MSDS/Airgas/CARBON%20DIOXIDE.pdf).

Adverse health effects (http://en.wikipedia.org/wiki/Theatrical_smoke_and_fog#Adverse_Health_Effects).

[zollen]

What about a chemical/pressure base endothermic cooling system. Is it possible??
The endothermic reaction triggers only when the system absorbs surrounding heat. Hopefully this would help the condensation problem..

[Sylvander]

Can you spot the fatal flaw in that?

Such a setup would have a fairly small limit to the total thermal energy it could absorb.
It might absorb it rapidly, or slowly, but it's ability to absorb would fairly quickly cease.
A bit like charging a battery or de-pressurising a vessel and then allowing it to suck in air.
Actually the air would push its way in under atmospheric pressure.
Just as heat "forces" its way [or transfers] into a cold mass of "sink" material due to the temperature difference between that and the high temperature "source" material.
"Heat is an interaction between a system and its surroundings due solely to the temperature difference between them".
That's the official definition as given by lecturers in Thermo-dynamics.

You need to think of it as a "flow" ["Heat" is thermal energy that is given that special name only when it is in transit (like "Rain")] that has the ability to continue pretty much unceasingly.
The rate of flow is determined by:
(a) The temperature difference.
(b) The thermal conductivity [reciprocal of thermal resistance].
In this case you want good conductivity = poor resistance.

[zollen]

Can you spot the fatal flaw in that?

Such a setup would have a fairly small limit to the total thermal energy it could absorb.
It might absorb it rapidly, or slowly, but it's ability to absorb would fairly quickly cease.
A bit like charging a battery or de-pressurising a vessel and then allowing it to suck in air.
Actually the air would push its way in under atmospheric pressure.
Just as heat "forces" its way [or transfers] into a cold mass of "sink" material due to the temperature difference between that and the high temperature "source" material.
"Heat is an interaction between a system and its surroundings due solely to the temperature difference between them".
That's the official definition as given by lecturers in Thermo-dynamics.

You need to think of it as a "flow" ["Heat" is thermal energy that is given that special name only when it is in transit (like "Rain")] that has the ability to continue pretty much unceasingly.
The rate of flow is determined by:
(a) The temperature difference.
(b) The thermal conductivity [reciprocal of thermal resistance].
In this case you want good conductivity = poor resistance.

I am very impressive with your knowledge of this subject. However I was thinking more of chemical/pressure hybrid model. Think of pressurized endothermic chemical that are capable to *absorb* unknown amount of heat through the two followings:
1. By de-pressurizing through a mini electric pressure pump installed in a PC (or outside a PC as a standalone unit).
2. By mixing (software controlled injector) exact amount of chemical/catalyst to enchance the heat absorbing property.

The tricky part is to re-pressurized the chemical and unmixed the chemical through some kind of chemical process. It seems this kind of system would be best fit externally. (standalone refrigerate unit)

Is this even possible?

[Sylvander]

Sounds like you're thinking of [something like] a very small refrigeration (http://en.wikipedia.org/wiki/Refrigeration) or heat pump arrangement.

This is where a suitable refrigerant [often Freon] is made to absorb and release the Latent Heat of Fusion and Vaporization (http://en.wikipedia.org/wiki/Latent_heat) by compressing and decompressing the refrigerant to produce a "Phase Change".
It's like...
When fine rain droplets solidify into snow crystals they give out [significant quantities of] Latent Heat to the surrounding environment [the air].
And when snow melts it ABSORBS lots of heat from the surroundings [again, most likely the air, or a body of water].
e.g
.
"But pleasures are like poppies spread,
You sieze the flower, its bloom is shed;
Or like the snow falls in the river,
A moment white--then melts for ever;
Or like the borealis race,
That flit ere you can point their place;
Or like the rainbow's lovely form
Evanishing amid the storm.--
Nae man can tether time or tide;
The hour approaches Tam maun ride;
That hour, o' night's black arch the key-stane,
That dreary hour he mounts his beast in;
And sic a night he taks the road in
As ne'er poor sinner was abroad in." (http://www.robertburns.org.uk/Assets/Poems_Songs/tamoshanter.htm)

Robert Burns, circa 1790 to 1796.
They were dangerous times! :(

This is used to produce a flow of heat from a source to something designed to reject heat to the surroundings.
Such a flow of heat can go on indefinitely, just so long as the surroundings are cold enough, not too hot relative to the source.

[Sylvander]

Forgot to explain Phase change or transition (http://en.wikipedia.org/wiki/Phase_transition).