h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Ok. I just heard about these Kryotech Cases (www.kryotech.com). They're a Computer case which cools your Processor to -40C! However The going Rate is US$2,400 and I can't afford that. They have a fridge built into them which Doesn't produce ANY condensation. My "How Do I" is How do I build a Fridge/Cooling System which produces no condensation?

I don't know about how kryotech does it, but doing a search for overclocking should produce some interesting things.
Try somewhere like http://www.overclockers.com and you'll find lots of ideas and links to how to do these kind of things yourself.

AntiJean asks: "They [www.kryotech.com] have a fridge built into them which Doesn't produce ANY condensation. My "How Do I" is How do I build a Fridge/Cooling System which produces no condensation?"

Jean, the answer to your question has to do with a very nifty and expensive (hence the $2,400 price tag) refrigeration unit. The part to note is the bit where they talk about having a "hermetically sealed refrigeration system" as well as the all-important wording of "condensation prevention technology" (on their spec sheet which can be had in .pdf format by following some links which I forgot to write down before closing that window ). In the practical world, the only way to not have ANY condensation when cooling is to not have ANY water vapor (aka moisture, aka humidity) contacting the areas that get very cold. In a very dry place, such as the Southwestern USA where I happen to live, we don't get much condensation even on a glass of ice water. When I was in Austin, Texas, you couldn't put a glass of cool milk on the table without it quickly developing a puddle of water around it. This all has to do with humidity, or the amount of water vapor in the air. Unfortunately, there is always SOME amount of water in our air. True, there can be VERY small amounts, but under normal conditions, it's extrodinarily rare to find dewpoints around -40 degrees Celcius (the quoted "cold plate temperature" for KryoTech's cooling system). By the way, the fancy term I just used, "dewpoint," is really just that - a fancy term. It refers to the temperature at which water vapor will form on a hard surface (more or less), and is really just a measure of how dry the air is. The less water in the air, the colder it would have to be for it to condense - or we say, the lower the dewpoint would be. A dewpoint of -40 C is pretty durn dry, and yes that there's a technical engineerin' term between the Mississippi and Rio Grande!

So, logically, there are two ways to eliminate the problem of unwanted condensation around a the cool parts of a refrigeration unit: (1) use VERY dry air. This is not really an option since dehumidifiers are expensive and themselves essentially use refrigeration cycles to intentionally condense the water out of the air then re-heat it - obviously wasteful for such a small scale application as a PC (2) isolate the coolest areas from outside air - this is what "hermetically sealed" means - an airtight seal. Hermetically sealing something with pipes and feeds coming in and out of stuff (like the exchangers and compressors and such in a refrigeration unit) is not all that easy, but is relatively easy and inexpensive on a small, PC-size scale. So, replacing the air around the fans with either VERY dry air that was dried somewhere on an industrial scale and put into all the hermetically sealed part of the system, or better yet, using an intert but harmless gas like nitrogen or helium or argon, you can get the desired cooling without having to worry seriously about condensation. Notice that they do not promise ZERO condensation, but that they have "condensation prevention technology" - in other words, they provide something that tries hard to prevent condensation (very very bad news for the innards of a PC!). I would wager there are a few caviats and legal-wordings to the effect of "your milage may vary" and "best results of using our system can be had in very dry climates, places like Abu-Dhabi and Albuquerque and the like".

As far as building one yourself, I think it's good advice to take a few practical engineering courses first, particularly in the areas of refrigeration and electronics working. Then again, by the time you'd have finished THAT, you'd probably have spent more than the cost of buying a unit from KryoTech, which is what they'd rather you do anway I'm sure. Heheh. By the way, I would strongly discourage anyone from trying to actually using refrigerated cooling on their PC's chip unless they really know what they're doing - remember, inside a PC, condensation is very very bad - you might as well lower haystacks of the boatdeck of the Lusitania!

-JD

I need to correct something I said: "This is not really an option since dehumidifiers are expensive and themselves essentially use refrigeration cycles to intentionally condense the water out of the air then re-heat it ..." This isn't completely accurate. It appears that only in very humid environments requiring excessive water vapor removal are regieration-cycle condensers used to intentionally condense the water vapor and thus dry the air. In many, "normal" applications it is sufficient to use a desiccant (drying agent) like bauxite or the like. Just FYI.

- JD

I've heard of people immersing part of their case in a nonconductive liquid (mineral oil is what they said, but I'd check on that before I did it). It will keep your processor down to under the boiling point of that liquid, which in many instances is less than the temperature it will achive without cooling.