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What Can I use to make a chiller/Cold room for my computer?

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matttheniceguy

Member
Joined
Apr 1, 2004
Location
Vancouver Canada
I'm offering this post (thread?) as a replacement for my now outdated "why a mini fridge won't work" sticky. I have seen a couple threads on essentially the same topic started lately, and they have turned to complete garbage/pi**ing fights for no good reason. Mods, if this does get stuck, perhaps remove this first paragraph. :thup:



So you want to build a water chiller? Maybe a cooled enclosure for your whole computer? Been eyeing some random cold making device at the local hardware store? Will it work?

There is only one key factor in this, heat load. The amount of heat the chilling object can remove must be higher than the amount of heat you are planning on removing. To determine if something will work, step one is to determine your heat load. If you are cooling just your CPU or GPU you will need to research it a bit. Ask in the processor/vidocard section and you will soon know how much power your are looking at. There are also some decent calculators out there for different cores and different speeds and voltages. If you are planning on cooling your whole computer, you can add up the power usage of all the different parts, or just look at how much power it is drawing from the wall. If you don't know any of that, how big of power supply does your computer need? All that power goes into heat, plus some extra from losses in the supply itself.

While these numbers will vary widely from hardware to hardware, and year to year, some safe numbers for a fully loaded system are 100-200 watts for a CPU or GPU, and well over 300 for a full system.

Next, you need to determine the heat capacity of whatever you are planning on using to cool the computer. Some products will simply list this capacity, usually in BTU/hr. 1 BTU/hr = 0.293 watts. Other products such as ice makers will list how much ice they can make in a certain time. It takes 80 cal to freeze 1 gram of water, or 93 watts to freeze 1 Kg in 1 hour. Other products will list nothing about capacity, so you will just have to go by things like how big its compressor is, how good is the condenser, and what sort of heat load is it designed for.

For something to work, it must have a capacity considerably larger than what you are cooling with it. Next is a list of common products, and the chances they will work. This is all assuming you are not going to modify the phase change systems in these products. Once you do that, all bets are off, and you may as well just build yourself a Direct Dye unit. There are of course exceptions to this list, be it an unusually powerful or well built unit, or low heat load that allows it to work.

Air conditioner - Well even 5200 BTU/Hr is over 1500W, and the compressors in these things are made to be run continuously. Even the smallest AC units are usually great candidates for chillers. If you want something cheap and easy to find, this is the thing to look for. The downside? Most are noisy and complete power hogs.

Dehumidifiers - If the capacity is high enough it can be a winner. It takes over 500W to condense 20L of water in 24 hours. If your planning on using one, it's probably best to post any specifications you can find on it first. Some will cut it, others won't.

Ice maker - Find out its thermal power and check if it's enough. Most small home units won't be, but industrial ones from restaurants will be. Also consider if the units is made for continuous use (home vs commercial).

Tap cooler - I'm talking about that wonderful device between the keg and your glass. Most units from a pub/bar/whatever have what it takes. Find one with a couple lines through it and have a working frosty tap on top of your rig. Best mod EVER. :beer: (note: the mini fridges with taps on top are not tap coolers, they are mini fridges with a hole in them)

12V ice chest - Those cheap little coolers made to keep lunch cool, forget it! These things use pelts that couldn't keep a hard drive cool.

Mini fridge - In general, no. They just can't handle the heat load of a modern processor. A few people have had success using surprisingly powerful older fridges, but for how long and on what heat load who knows. I'm not saying it can't be done, but it's a snowball's chance in hell for most systems and most fridges. The compressors aren't meant to run continuously so there are some issues there as well.

Full fridge - Not too sure on this one. From the size of the compressor and the design of the condenser I would say no way. There may be some fridges out there that could take it, but I wouldn't expect most to.

Freezer - In most cases, no. Some huge industrial meat flash freezer my be able to do it, but if it's white and sitting in your house, no chance. They can reach low temperatures, but they do it at the cost of capacity.

Water Cooler - Usually not. The compressors and condensers are too small. A stronger office type unit may have the capacity, but most home ones won't.

Got some other device and want to know if it will work? First try and figure out its capacity. A good Direct Die (efficient) system uses a 1/4 - 1/2 HP compressor so unless your device has that it isn't looking good. Want to ask the forum? Go ahead, but come with some knowledge. Saying things like "with enough imagination anything can work" is just going to annoy people. Look at your device's designed heat load, what you are trying to cool, and see if the numbers work. If they don't people will be more than happy to help you come up with something that will work
 
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Great post :thup:

I'll make a little contribution too. I have found this most helpfull in my chiller projects when it comes to coolant which for me is now methanol/ethanol cut with distilled water as there is nothing that works better that I found yet, methanol mix being the prefered.


Methanol / Distilled Water Coolant

Methanol concentraton Volume %................Freezing Point F (C)

0..................................................................32 (0)
13................................................................20 (-7)
24..................................................................0 (-18)
35...............................................................-15 (-26)
46...............................................................-40 (-40)
56...............................................................-65 (-54)
66...............................................................-95 (-71)
75.............................................................-215 (<-73)
83.............................................................-225 (<-73)
92.............................................................-230 (<-73)
100...........................................................-145 (<-73)



Ethanol / Distilled Water Coolant

Ethanol concentraton Volume %....................Freezing Point F (C)

0...................................................................32 (0)
8...................................................................25 (-4)
17.................................................................15 (-9)
26...................................................................5 (-15)
34................................................................-10 (-23)
44................................................................-25 (-32)
54................................................................-35 (-37)
65................................................................-55 (-48)
76................................................................-75 (-59)
88..............................................................-110 (<-73)
100............................................................-175 (<-73)
 
Good info Professor.

I guess I should also mention that for anyone planning on putting their entire system in a cooled chamber (like a freezer, fridge, whatever) there will be some serious complications. Hard drives and optical drives don't like being that cold, so they have to be put outside. If you are getting things REALLY cold (like -40) you will need to chage a lot of capacitors as well. Other than that there is also condensation. It won't form easily on your parts (which will be the warmest thing in there), but it will form all over everything else, and eventually some hardware is bound to come in contact with moisture from somewhere, and then it's game over. It's another thing that can and has been done, but most people (even those who have done it) agree it isn't worth the trouble.

If you just HAVE to cool your whole motherboard/ram/videocard, take a look into submersive cooling.
 
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