Some Questions About Phase Change

Hello All,

This looks like it was once the hot place to be for phase change cooling :D I wonder why it seems to have mostly died off?
Anyways, hopefully some of you are still around who could lend me a helping hand.

I'm working on designing a case. It'll house computer and single stage unit as well and some basic controls. I've made sure it's a little large for potential upgrades down the road. I'm still learning right now, but at some point in the future, I'd like to have a 2 stage cascade system.

I currently have a compressor, condenser and I'm in the process of getting a chilly1 evap from Ron (heard great things, so I'm excited :) )

So, question 1.
I noticed on some builds, there'll be tons of coils of copper, like on overklokk's two stage seen below:
http://i.imgur.com/Kx42bdu.png
http://www.xtremesystems.org/forums/...ade-in-progres

What is the purpose of this? Why do some builds have this and some not?
In a build guide from overclockers.com, they put a single loop in the copper pipe in order to dampen vibrations coming from the compressor. I assume there's a functional reason for these coils apart from vibration dampening?


Question 2.
How do you go about determining how far you will run a compressor over spec?
For instance overklokk was running two R134a compressors with R507(I think) and R1150. Now, I probably wouldn't want to go grab any random compressor on ebay and load it up way over spec. So what are you looking at to determine if the compressor will handle it?


Also, any words of advice for my first time building a phase change system?

That's like an 11 year old thread you linked to :)

Most of the phase change stuff died off because lack of builders and some with sorted stories. And also because must CPU's now a days simply will not benefit from going extreme cold. Its a lot of work with little payoff as far as OC's go. Unless you want to hunt down a binned chip.

Cascades are great, I had one here for a while. I lost interest as many CPU's I got cold bugged at the sight of an ice cube. I would not recommend a cascade for everyday use, the noise, heat output and power draw will soon overwhelm you.

Also if this is your first build I would not recommend it, they are complex builds and require gasses that are expensive and hard to get. Stick with a Single Stage which are much cheaper to build and run.

Good luck

First, Hello to all my longtime friends at XS.

In my opinion there are several reasons why the site slowed down. The Biggest was predictable, PC's used to be so slow people that used programs like auto-cad or graphic artist and so on sometimes spent hours watching the hour glass on windows waiting for the computations to be done. IF you cooled a chip of that era and overclocked it you may gain 40 percent more speed. Now with the multi-core chips, you can buy a off the shelf PC that more than meets most people needs. That said, just like many people like fast cars and like to race them, some like fast pc's and race them.

Coils in copper tube are used for many reasons, from rejecting more "heat of compression" to adding more "sub-cooling" and dozens more depending on what your building.

wdrzal is back !!! :)

The coil reduces vibration that can damage joints over time, it adds a small amount of volume, the compression of the gas creates a lot of heat and the coil offloads some heat before the condenser.

Danfoss compressors have been the best "Danfoss sc12mlx" low temp compressor has no restart delay and acceptable noise level.

Americold compressors are hard to find but I feel better than Danfoss for SS.

It is possible to find SS on ebay still and then transplant the guts into your case.

When considering a cascade, shoot for maximum capacity and no coldest temp.

R507/R1150 is the most common gasses for two stage.

I have de superheaters before the HX, 1/2 ton TXV expansion valves, expansion tanks to add volume plus I can pump all gas into them if I have to cut the system, brazed plate heat exchangers, braided stainless line set, 1/8 inch liquid lines with 1/4 inch discharge lines. Plus a few more tricks.

Quote:

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Originally Posted by Buckeye

wdrzal is back !!! :)

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Never really Left........Keeping a eye out if someone tries something Dangerous......

Need to spend more time here @ XS to catch up on the new generation of computers, OS ,networks servers ,security and so on. I need to build 2 business systems. each will use 5 to 10 PC's.

I have a few questions, I'll ask in the relevant sections. There is a lot of great people here @ XS and thanks to FUGGER for maintaining this site.