An A/C system for my computer case... can it be done ?

I've been wondering lately, I have quite a new PC with a high spec, but the problem is, the faster the component's and CPU's that go into PC's and motherboards - the more heat they chuck out.

I was thinking, Is it possible to find a working fridge, and disassamble it, and using the parts to make an A/C system for my PC's case, my main questions are:

1) Is it easy to connect all the components and copper tubing?
2) Is it a safe thing to do, IE, fire risks? electrocution?
3) How easy is to 'gas-up' the system? (I need a friend who is a refrigeration engineer...)


I visited the tip a few weeks ago, and there was what looked like a compressor/fan/radiator unit there, painted black, looked nice...
I only wished I got it now! :rolleyes:
What are the chances of finding a working compressor, for free, or very cheap?

Thanks in advance!

-Dave ;)

PS, this was posted in the refigeration section, but I just noticed that there was a A/C section, lol, sorry about that!

Computer components are designed to run under near room temperature conditions. A small squirrel cage type fan, pumping room air through the computer case would no doubt be sufficient.

If you felt that you needed mechanical cooling, fridge components would be a poor choice. You would be better off with a small A/C unit (window shaker) with it's cool air output pointed towards the computer case, or ducted into it.

Is it easy to connect refrigeration components? No.
Is it safe? No.
Is it easy to "gas up"? No.

Better to leave the A/C unit intact and direct it's output.

Correct me if Im wrong ....... (red rag to a bull) :p

I believe that there is a AC unit for the larger PC's. I am sure I've read about this. I will go and have a look.

Thanks for the reply Gary ;)

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Computer components are designed to run under near room temperature conditions. A small squirrel cage type fan, pumping room air through the computer case would no doubt be sufficient.

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That was the case back then when we were all using 486's... ahh the good 'ole days....

You have'nt seen some of the things people have done to thier PC's cases yet then, LoL

We're talking about people cutting holes in cases for large fans to blast air into the system, and yes, they've already done it, water cooling... there are kit's available that allow you to water cool your CPU and case.

So I thought, why not go to the next step, AC systems for your PC!

A 'window shaker' as you call it, I think you mean a window AC unit, not many of those over here in the UK, very rare.

Is it easy to connect refrigeration components? No. *** Not even using pipe soldering skills ?? we had an engineer fix our fridge once, he replaced the expander and had so solder up the pipes and re-gas the fridge

Is it safe? No. *** How do you make it safe? / what is the dangerous part(s) ?

Is it easy to "gas up"? No. *** an engineer did it to our fridge once, he had a cyninder of the gas, and a large white box that I would suspect to be another compressor to put the gas into the fridge

Oh well, there's gotta be a small way to do this... there's not much difference to repairing a fridge.

Another option, use a peltier to cool water, or some other fluid, and pump that round a radiator in the case.

-Dave

If you want to refrigerate your pc case, then no problem. Just get the largest case you can, I think they call them Tower cases. Now get in touch with Telecom companies. I was at Telkom Geneva some time back. Telecommunication racks are often cooled with *****. The compressors are tiny and yes, the rack has its own little refrigeration rack built into it to cool the electronics within it.

The technology is available, I do not have information at hand who the manufacturers are, but surf the net and you shall find. And dont even think of it if you want to scrimp on the costs, at most it will be unwieldy and will probably cause you more distress, if you get some bits together and get your mate to put it together. Im talking about moisture here.

Best solution is get a large fan, the type you get in frost free refrigerators, about 6" square, and this will work perfect, on the other hand if you want to make a million by inventing a refigeration system for PC's then by all means dabble. And I say again, it wont be cheap.

Thats my tuppence worth.......

Let me rephrase my answers, then.

Is it easy to connect refrigeration components? Yes, if you know how. No, if you don't.

Is it safe? Yes, if you know how. No, if you don't.

Is it easy to "gas up" a system? Yes, if you know how. No, if you don't.

Every profession you can think of is easy for those who know what they are doing.

You seem to think repairing a fridge is easy. Try it. Remove all of the components, and then put them all back together.

Then call someone who has sufficient training and experience to make it look easy, and who will charge you accordingly.

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Originally posted by electro
I think you mean a window AC unit, not many of those over here in the UK, very rare.

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There are quite a few over here actually.

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Another option, use a peltier.........

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You could use one of these directly mounted on the PC casing.

Really though I would the best option is to trust the PC manufacturer in having constructed and tested his product to work in most suitable conditions.

The worst thing that computers suffer from is rapid changes in temperature; the disk drive changes size and won't read or write. Steady conditions, within design limits, are best. Put AC in the room and enjoy the comfort cooling yourself at the same time.

All of the PC components I am aware of are designed for near room temperature, and can therefore be cooled with room air. Problems arise as people add on more components and/or more powerful components. The heat load inside the case is greatly increased without increasing the exhaust air.

PC's are equipped with propellor fans. The logical next step would be a squirrel cage fan. Something along the lines of the flue vent fan found in high efficiency furnaces.

The problem with a propellor fan is that it has poor throw characteristics. It cannot push against a positive pressure, nor pull against a negative pressure. A squirrel cage fan can do both. Squirrel cage fans made duct systems possible.

I think the clue here is to look at his bio.

One of his joys is "overclocking" this is the act of speeding up the cpu over and above the manufacturers specifications :D

This in turn produces a lot more heat, so much so that, if one is not careful, one can burn out the cpu ...... quite costly.

ive been thinking about refrigerating my pc too. large supercomputers are also airconditioned. watercooling (for me) its too messy and i cant afford the piping, radiators and waterblocks.

though, i can get many small cooling units from refriderators (the compressor and the radiator thats udner the freezer) for free.

i used to have a 1/8hp compressor that was 4"wide, and 6 inches long (it was shaped like a sphere). it wouldnt be too hard at all if you have the right tools and if you know what you are doing. i looked up the MSDS for 3 different refrigerents (*****, R22 and puron) and their all rated level 1. they dont ignite, they dont burn, explode or harm you in anyway. they only warning was frostbite.

in order to do this, you would need large amounts of styrofoam for insulation. just place the radiator outside the case, and the condensor at the top of the case, and have cold air blow downwards.

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Originally posted by Brian_UK
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Really though I would the best option is to trust the PC manufacturer in having constructed and tested his product to work in most suitable conditions.

The worst thing that computers suffer from is rapid changes in temperature; the disk drive changes size and won't read or write. Steady conditions, within design limits, are best. Put AC in the room and enjoy the comfort cooling yourself at the same time.

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trust the pc manufaturer? they didnt build their cooling system in the pc for extreme overclocking.

(but i do see what could happen when the pc is cooled too much)


Have you visited www.tomshardware.com ? theirs a P IIII thats been overclocked to 3ghz. that would need an extreme bulky cooling system, like a freezer if watercooling isnt an option.

also at tomshardware.com, (if you look hard enough) their is a website where someone put the motherboard of a 486sx inside a small freezer and set it to max, then overclocked the 486 to ... was it 400mhz?..... anyway, some people with shallow wallets (like me) and a spare freezer should (could) use an A/C system to cool a pc. but, a negitive side of using an A/C unit is the cost. my OLD 8500BTU used 1330W@120v, but 8500 btus is too high for a pc anyway...

im going to take my PIII computer from 450 to 1200mhz (if it lets me). i have some bios where you enter in the speed, or you can set jumpers for a 12x mult and your bus speeds...


"we" could always set the cooling unit to 55-60*F. all of my pc parts are rated for 50-120*F anyway.could could

The original post didn't mention overclocking. That is an entirely different proposition from cooling the case. The trick is to design an evaporator to transfer heat from the heat producing component(s) to a refrigeration system.

Here's a question for the overclockers:

Why not build an extension cord for the CPU, bring it outside the case and stick it in a freezer?

hmm.... well, i need an airconditioning system for overclocking. i plan to build one for a friends tandy that he overclocks into the ghz range. it ends up melting like ice-cream.


if electro isnt doing something that heats up like my friends tandy, then electro should get a small squirrel cage fan, a dremmel cutter, some duct tape, and some small ducting.

12v squirrel cage fans for computers can be found on ebay for
~8$. cheaper than a refridgeration system. and ducting? dig around in some dumpsters near a HVAC dealer (its legal only when the dumster has been set on the curb. its considered public domain when it is, when it isnt.... its not free stuff)

and to cool the case below room temperature, why not run to ebay and buy some peltier coolers. theirs 4 thats stuck on a large heatsink that ends in a few days thats at 12$ (still cheaper than a refridgerator, and much quieter)

This link: http://www.novelconceptsinc.com/contents.htm was very interesting

Hi Gary,

I'm not an electronics wizard....but the placement of the cpu is extraordinarily important on the circuit board....it isn't possible to change any of the lengths or else the timings between the cpu and the memory, the chipset, etc are thrown off.

There is a manufacturer who has done the opposite of what you suggest - Kryotech builds a computer case in which the bottom is a compressor/condensor, and a airtight chamber is clamped onto the systemboard around the cpu....and only the cpu is kept at around -50C....as the cpu will continue to improve in performance until it reaches a plateau at around -80C.

There is another company who makes the Vapochill that I have mentioned before....that uses an evaporator directly in contact with the cpu to chill it. The restrictions there are a relatively small contact area, and the challenge of safely engaging the evaporator onto the cpu....perfectly level...and without grinding or crushing it.

Folks....by FAR the easiest method to use phase-change for heavy overclocking is by using a water/glycol mix...running watercooling over your cpu/chipset/gpu and using the actual cooling unit to chill the water - external from the computer. Your only challenge then is to insulate the lines.

How much is the performance improved by cooling down to -50*C?

That kind of cooling basically removes the cpu as the bottleneck in your system. If you have chosen components that can handle being run at higher than spec, you might be able to get a 50% overclock with extreme cooling.

It really isn't financially viable - it's cheaper to build a dual-cpu system, or get a second computer than to supercool a single one. Like any hobby, there are those of us who want to see how far they can go....for the challenge and bragging rights.

Me, I want to have an Athlon cpu running in excess of 2 ghz, with my current equipment (not waiting for a 2ghz cpu to be released).

Okay, here's the next question: Can a Pelt (hot junction) be extended outside the case?

I assume Kryotech is using a two stage system to achieve -50C. To get to -80C would probably take a cascade system. Feasible, but very expensive. Using a Pelt for the low stage might make more sense.

A peltier, (TEC) can be extended anywhere you can provide enough current....I would assume.

I'm building my phase-change rig (the direct evaporator-contact type) such that I can utilize a 156W peltier cooling the cpu and the evaporator cooling the hot side - IF I decide that the evaporator isn't able to cool adequately by itself.

BTW - I do have 2 1/10 hp compressors available....I'm currently building a system that only uses one, that has a lower evaporator temp (-25C to -5C). How much benefit would be achieved by redesigning the system to be dual phase?

Yes dual staged system will get you much lower temps.
My current system that will be chilling my computer is a dual staged cascade system.
Although the cascade system does have a leak.Probably one of the flare fittings.But I am going to scrap that and go with a dual staged cascade cooler.
So that is 4 compressers altogether heh.

2 of em are 1/2hp and 3/4hp.The cascade compressors are 1/8hp and the other one I am not real sure of.Got it at a junkyard and no ratings on it anywhere.I am hoping it is bigger than the 1/8hp compressor.
It currently gets below -60F
I need a better thermometer though.

Also I dont think Kryotech gets -50C ;)

Oh yeah I am not sure if having the same hp compressors as a dual staged system would work as good as having say, a 1/4 and 1/8hp.
You could also make a cascade system out of it.I know a killer way to cool the condenser of the first system :)

What refrigerant(s) are you using for your cascade?

R290(propane)
I think if I mix it with R134a I will get a much better temp.

I assume you're talking a 2-stage chiller, and actually running a water/glycol mixture to cool the cpu?

I'm paying close attention here.....next time I build one of these, I could well try a dual-phase or cascade system. Any tips or tweaks?

Yes a Dual phase/dual stage.Means the same thing,dual compressors.But it is also cascade,I am going to remake it today so the cascade chiller will also be dual stage :)

Gonna be big heh

Actually, a two stage system has two stages in a single compressor. A cascade system is two (or more) systems in series. The high stage system cools the low stage system which cools the medium.

I don't have a P/T chart for propane handy. What low stage pressures do you typically run at -60F? Why do you think mixing it with R134A will help?

Sounds to me like a classic autocascade system... 134a and Propane. But that would be with one compressor and an additional heat exchanger.

I mean dual stage as in each compressor as a stage.
I guess I will call it dual phase ;)
The reason adding R134a should help,is because Propane is lighter than R12.So R134a should make it a bit more heavy.I think,I dont have charts for it,but I remember that someone used propane and it didnt even cool with propane until he added R134a....

Now my system has 2 compressors for the main waterchiller.
Then a seperate system cooling the condenser.

The system cooling the condensor is also going to be dual staged.

I dont know if I am going to add R134a or not....
R22 works alot better than R290,but I ran out.But since the r290 is going well below -60F I guess it is working ok....

Low side psi is around 16-20 inches and high side with new smaller cap is about 75psi I think.With the old bigger capillary I got about 5-10psi high side....
Those are probably a little off..
My cascade cooler has a leak so it isnt stable.

Something is stumping me right now,what are the pipes coming out of the compressor?Steel or something?
Silflo will not stick to it,and brass melts at too high of a temp and burns a hole in my copper. :)

:D Wow! Just what is it we are trying to cool down? An A/C system in a computer case? I thought the multi hole cut case with several 4" fans was a little overkill. A great site for PC cooling and over clocking is "maximumpc.com". I do believe they have a design for a heat pipe that cools the proc no matter what the freq is. Additional case cooling is supplied with fans which should be more then whats needed for today's super chips. I would personally keep any running motors far from the PC except the 12VDC fans. Were haven't reached micro wave freqs on the proc yet...I think then we will have to do something about further cooling down the PC.

Again, merely putting AC into the case - having ambiant temps of close to freezing isn't terribly practical. Having to try insulate the entire case to prevent condensation isn't something I'd like to try.

Using AC to cool the cpu either by direct contact with the evaporator, or by using an external chiller to cool a liquid that is then used to cool the cpu (chipset, vga, etc) is more practical - as much as using refrigeration to supercool for the purposes of overclocking, where normal high performance HSF are currently use - can be considered practical.

Seems like there ought to be a better way. I wonder if the entire motherboard could be attached to an extension cable, dipped in plastic to seal it, then stuck in a freezer.

There are those who have played with entire motherboard immersion in a non-conductive fluid....cooled by an AC unit. You have to make sure the drives, power supply, etc aren't in contact with liquid or the cold.

Somewhat harder to use this long-term...having fluid that is open to the air...could potentially involve bacterial growth.....etc. It's easy to build an enclosure to house the AC that can sit beside a computer, compared to building an enclosure to house an immersed motherboard.

I'm thinking that if the motherboard were separated from all other components (joined by extension cable) and tightly sealed, it wouldn't need to be immersed. It could simply be placed in a conventional freezer.

I agree....this is possible. Basically I believe the limits would be the cables to the hard drives.....the official spec is they can't be longer than 18", although many people use cables up to 36". Extensions can be purchased for the ATX power, which would allow the drives themselves to stay outside the motherboard chamber.

I assume you would intend us to continue to use a heatsink and fan inside the freezer? Unless the freezer temp is quite low, I don't think it'll be able to pull enough heat from the tiny point that is the cpu.

I'm sure a tiny, high-power freezer could be built (by you expert types :) but are they available commercially? Motherboard size is roughly 13" x 20", and would need to be about 6" tall.

Cooling can be concentrated at the tiny cpu with a fan, and that tiny target can be expanded via heat sink, heat pipe, or Pelt.

Small freezers are readily available commercially, and can be modified for the needed capacity and/or temperature range.

The big advantage to this approach is to be able to overclock without having to become a refrigeration expert.

By modified...you mean taking a freezer to an HVAC shop or tech who would adjust the compressor/condensor/refrigerant to reach the desired amount of cooling?

I know it's asking the impossible....but along with good cooling, I was hoping to do this without spending too terribly much money. I know when I started off pricing out compressors and condensors, they rapidly escalated out of my price range. That's why I started with a used setup that I was able to find locally. I'm willing to do some learning to assist on the project....but ultimately I realize I'm not going to become an expert, just for a single project like this.

That's why we keep pestering you fine folks with our questions. As I've often said before, your assistance is greatly appreciated.

Generally a small freezer should be able to handle the heat load, but if you want it to go much below -20F or so, modifications will be needed. The lower the temp, the more expensive the modifications.

I don't see it as pestering at all. It's interesting stuff. :)

Generally speaking a powerful processor is going to be making something like 100W of heat, the various other components on the motherboard perhaps another 30W, the video card making perhaps 40W of heat......what exactly would it take to keep a chamber of dimensions like I listed....below freezing? While there are some who really desire extremely low temps, there are decreasing gains in performance as temps decrease. Most decent heatsinks can keep a cpu within 10-15C of ambiant temps....if it's all stored in a freezer at -10C, that should yield pretty good results.

Can I buy that in a pre-made solution...and for a reasonable price?

I would guess that you probably have such a wonderous machine sitting in your kitchen. Just stick the motherboard alongside the frozen dinners. :)