Phase change compressor horse power?

[evowatercooling]

What should i look for when finding a good compressor. I am going to be using it as a water chiller if that helps. Also does the compressor size effect the length and size of the capillary?

Thanks for the help!

[nealric]

1/4 or 1/8 will do you fine.

1/12 would probably work, but thats a bit weak.
Dont go over 1/4 because anything bigger than that will be way too loud, power consuming, and large.

I wouldnt know about the capalary. a good person to PM about that would angiema sp? Hes a mod on the phase-change.com forums if you need him.

[Severian]

Heh, if you ever have a read of www.phase-change.com you'd think 1/4 was the minimum :P

It depends whether you want to be able to hide away your compressor in your case or not.

But to be honest, not wanting to play down this place in the least, the technical specifications of compressors is a very...technical subject. That website I mentioned earlier is the really only place that you could get advice which I personally would trust.

And yes, it does effect the size of the capillary. The size of the capillary is supposedly the black art of making a phase-change system, so...

[Gautam]

The original Prometeia(aka Mach I) uses only a 1/9hp compressor, and R134a, yet performs very nicely. However, the rest can get very technical.

[aenigma]

Okay 1/4 is the minimum if you are looking for great temps.Anything bigger than 1/4 is not big and noisy unless you are talking about an a/c compressor.
1/8 is puny but it will work, just not as good as most people want.

The prometeia doesn't perform nicely.Most people are fooled into believing it works wonders, but they always look at the evaporator temperatures.(the tmep readout on the front of the case).Those don't mean a thing.Most of the time they read from -35c to -40c but the cpu is actually above 0c.

Compressors are not what you use to find correct capillary sizes.It does play a part though.But there will definately be a differance in capillary sizes between a 1/4hp and a 1/12hp.But the average compressor people use is at least 1/4hp.

The type of refrigerant and heatload play a bigger roll in capillary sizes.The best way to figure out capillary sizes is to start off with the full roll and measure subcooling and superheat, that will get you in the ballpark.Then you can get it charged correctly while cooling the heatload and go from there cutting the capillary down if needed.

[Gautam]

I understand that the Prometeia doesn't perform very well in comparison to a DIY system that use a 1/4 hp. But bear in mind that most of us here use no more than straight water or air cooling. Even Prometea-level temps are generally more than good enough for most, and as such, 1/8hp compressor would probably suffice for most.

[aenigma]

Well, the temps it gets are lousy for the price of the system.If the prometeia was alot cheaper then I would understand it, but you just don't pay that much money to cool your cpu to 10c.

[Gautam]

The cost of a 1/8hp is generally a lot lower than a 1/4hp one. Also, bear in mind that he is looking for a waterchiller, which, AFAIK, will not be as taxing as direct die.

[aenigma]

If anything, a waterchiller would need a larger compressor due to parasitic heat gains through imperfect insulation.

The cost of compressors is irrelevant in our case, the majority of compressors I have collected were free.The only one I bought was only 20 bucks,it was also pretty new(2000 or 2001) and had never been used.

[evowatercooling]

Thanks for all the information guys. What i am looking for is something that will fit in the case. I will be using the lian li pc70 case so there is a lot of room (dont know how wide it is though). Anyways i am also looking for best performance with good looks. I am starting out with water cooling cause i want to learn a little bit about tweaking a phase change unit before going direct die.

With the compressor size i just wanted to have a ball park so that if i did come apon a cheap one i could tell if it would be worht while to get.

Thanks again

[Severian]

Hmm, aenigma, where do you peak up compressors for free? The local scrapyard?

There's a dealer near me with a large selection of new compressors, but they usually cost like $150 (converted from £'s), so anyplace to get a free one would be great.



The biggest advantage of Vapochill or Prometia is the software that comes with it - automatically controlling your temps. Also their evapourators are generally better than you can make by yourself, especially in Prometia's case.

[aenigma]

I get compressors free from junkyards or window air conditioners.When people get new air conditioners or freezers they usually just toss their old one, and that is a great place to get a compressor.

The software that comes with the vapochill and prometeia doesn't control temps, it controls your computer.It starts the computer when the cpu reaches a certain temperature, and shuts it off if it goes above it.Hardly worth paying all that money though.

The evaporators are not better, the vapochill I believe is just a hollow block, and the prometeia is like a heatsink.Not a real good design.Alot of people can make a maze block, which is a much better design.

[Severian]

Yeah, I just had a read of the thread on XS about how Bowman is modding OPPAINTER's Prometeia - the evapourator they use is really really basic...

I take it your system is a home built phase-change rig? How do you control the boot up temps, or do you just have two on buttons? :)

[aenigma]

Well actually I am air cooling now, I don't do much with phase change anymore.At least not with my computer.But when I had it running I just turned it on before my computer until cpu temps(thermistor on the cpu die) dropped to an acceptable level.But I never shut my computer off, so I didn't need any controller.

[migginz]

you need a bigger setup to chill water than to direct die.

[aenigma]

No you don't, not if you pay close attention to insulation.I would always prefer a bigger setup though to get the lowest coolant temperatures possible with all the drawbacks to chilling.Alot of people think water chillers need large compressors and that is a myth.