Planning Air conditioned water loop (phase in res)

ive decided water cooling isnt good enough, for less money i can get a cheap AC and put its phase cooled rad inside a large res connected to a standard loop, eliminating the need for a rad and hardcore fans ($200-300 vs $0-60).

ive looked through the index and used the search but i cant find anyone that has done this.

i would like to know what issues i would most probably run into, like temp control for example. i figured i could place the AC's temp sensor in the water, which would allow the AC to shut off when it was cool enough.

i would like to aim for around 9C so i dont need to insulate against condensation.

also would i need to worry about what liquid i used in the loop? should i even consider using distilled water with an anti-corrosive or should i use a liquid that operated better at lower temps?

 

http://www.bit-tech.net/hardware/cooling/2010/07/20/hailea-hc-500a-water-chiller-review/1


Searching would have found this little chap.

 

thanks for the reply, ive read that article already, but its not the same as what i want to do. i want to dismantle an AC and place the rad inside a large res which will feed a water loop.

i was wondering if anyone had renovated an AC or other phase changer to work with a PC cooling setup.

ive pretty much got it figured out, but i guess il have to start testing on my own.
il keep looking though.

 

a water chiller is exactly that.

however a cheap AC i don't think can handle the thermal load your asking from it, it will be running its compressor around the clock.

 

lots of people have done that, that link is just a commersial phase change system

 

yes yes, but what i was wondering is if anyone has done a conversion from another commercial device (AC), with a log or something.

its not hard to find people in my area that just want to get rid of one, im picking up an 8000btu ac for free later today, which should be much more powerful then the Hailea.

 

This would be my suggestions. Other, more experienced extreme coolers feel free to step in and correct me.

-Put it in another room, so you don't have to listen to it

-Use a powerful pump, not a wimpy little 12v one, so you can run high diameter tubing and run it to another room

If my calculations are correct, an 8,000 BTU air conditioner can cool about 2300 watts. Your computer is only a fraction of that, but obviously you don't want the compressor running around the clock, nor do you want it to turn on and off every minute.

IMO, you would be best off with a very large reservoir to put the heat exchanger in. Like a barrel or something. A well-insulated barrel. Build a microcontroller using a cheap digital thermometer and a relay, and have it turn the air conditioner on when the water is above like 20 C, and off when the water is below 10C. This way, the compressor will run when you first turn it on, but the large volume of insulated water will allow the compressor to turn off during light use. You don't want to be burning up all that electricity when you're just surfing the web or something like that.

During the winter, put the assembly inside your house. It depending on the COP of the air conditioner, it will help to keep your house warm. During the summer, put the hot exchanger in the window, otherwise it will heat up your house.

 

thanks for replying altron.

yea, thats exactly what i was thinking, stick it in a barrel, not a large one but big enough to take a while to heat. then have it in another room.

is there like a formula for flow rate based on the distance and size of the tubing? i dont know exactly what type of pump too look for.
i was looking at this one, a reviewer said his pushed 360 litres/minute or about 9-10 gallons/minute but i think i could get something better for less money, and you say 12v isn't good enough.

and then theres the coolant. i want something that will work well at lower temps, like 0-20 but will also do sub zero if i want.
if im going to fill a small barrel im not going to spend $15 a liter for a feser coolant or something.

should i just use some mixture of antifreeze? some other guys were saying too dilute it with water to make it thinner for flow rate. should i dilute it with distilled water?

another thing is it would probably be best if i didn't have to take everything out of the AC, like remove the compressor condenser and evap then reassemble it, but if i did would it be that difficult? im reading lots of guides on how to do this, but this would be my first time dealing with this.

i know i would have to take it all apart to move stuff, but basically im wondering if i should just start cutting pipe and fit it the way i want or if theres a change i wouldn't need too.

 

you don't want to go blow the dew point of the air (the point at which condensation starts to form) unless you've seriously waterproofed your PC...

also water will be thicker than antifreeze and you could just use deionised/distilled water with some algicide or some such in it - you'd have to check it wouldn't attack the blocks though!

 

you can just mix the distilled water with an anti-corrosive which would probably include an algaecide. im just worried about cost for like 10 liters for example.

im not worried about water proofing, but i dont want the water to freeze. (im familiar with condensation/dew-point based on temp diff and relative humidity)

 

I'm a little oldschool - I was on the forums before 12v pumps took off. The original WC setups most people had used Eheim 110vac mains powered fountain/aquarium pumps and junkyard car heatercores with homebrew milled waterblocks. After a little while, aftermarket 120mm or 2x120mm rads and waterblocks came out, but the 110vac mains pumps were still what everyone used. It wasn't until Koolance, Swiftech, and Thermaltake started coming out with the pre-assembled kits, those guys used 12v pumps to make in-case installation easier (before you'd have to run 110vac mains into the case). Upon becoming active on the forums again, I was surprised to learn that few, if anyone, still used mains powered pumps. The popular brand was Eheim, but some people used AquaVia, Danner, or Hydor too.

This was my reasoning
1 - Distance. You need a stronger pump for longer runs of tubing.
2 - PSU load. 12v pumps are more load on your PSU. 110vac mains pumps are not.
3 - Noise. Having a mains pump allows you to place it with the air conditioner, not inside of your PC
4 - You can use a submersible pump, which runs cooler.

This thing was all the rage in like 2003, when watercooling was taking off.
http://www.marinedepot.com/Eheim_Un...ble_Water_Pumps-Eheim-EH1046-FIWPSBUF-vi.html

 

well i was prepared to spend around $100 on a pump, it looks like the Eheim 1048 Pump
is only $10 more and its 79 gph vs 158 gph. would 158 gph mean more stress on the loop? is it enough to worry about? like for example what should i not exceed pressure wise?

il probably leave the pump outside the res but this one gives you the option. i dont want to be limited by the pump, even if i up scale it a little so il probably get that something like the Eheim 1048.

right now im liking 158 gph for $76 vs 65 gph for $120.

 

Just thought I would chime in with some suggestions to help out your AC dilemma. If you want to make it a bit easier on yourself with dismantling the AC unit, why not build a custom res around the rad of the AC unit. My thought goes something like this.............2 reservoirs, one on the AC unit, and one larger one to supply the PC. would take 2 seperate pumps, one to circulate back and forth with the PC, and one to supply the liquid back and forth to the AC unit. If you set up something like that, you could have your large res closer to the PC and running a smallish 12v pump, like a current 'traditional' WC setup. And then use the larger pump and AC unit to cool the large res, and just run the tubing to wherever you need to put the AC unit. This would also allow you to minimalize the changes to the AC unit, and even hang it from a window like you would if you were using it to cool a room. Difference being that instead of pumping air across the AC heat exchanger, you would have a custom rex built around the AC radiator.

Sounds a bit complex, but I feel that it is actually a simpler solution to the problems that arise from modding an AC unit, especially since the ones im familiar with use brazed copper fittings and tubing. One small mistake and you will dump the freon charge.

 

thanks nanosec, but i think i can do this with building one res.

oh and the pink is the res

this is how its gonna work, i might have a small res in the waterloop to help remove air, not sure yet.

im still not sure how powerful the pump needs to be, would 150gph be good? should i go higher?

 

Here is a link to a thread where a bunch of people have converted AC units to water chillers. It is a cross-forum link, which I think is alright here. If it isn't, mods, I am sorry.

As for pump selection, then it depends on your temps. Be aware that some lubricants and pump housings don't like being really cold (as in sub-zero). Also, in water cooling, pressure over flow. Then again, my Eheim 1250 goes like a champ.

For coolants, you can't really go wrong with denatured alcohol (methylated spirits), really low freezing temperature and decent thermal characteristics. If you are not going really cold, distilled is always the best.

Gool luck,

Laz

 

Langer was toying with the idea of using a lobster tank cooler. They have a built in thermostat you can set to ambient temp.
At the same time, it might be easier to just get a big AC core from a scrapyard and run it passive/fanless.

 

Agreed. The AC will Cycle on and off... so can your computer cooling go 10 minutes with out a cooling hit?

.. no

 

well thats why im going to cool a large, insulated res. ive pretty much decided how its gonna work.
and im gonna test the ability of the AC before i get everything else together.

thanks for the link and advice on coolants Von Lazuli

 

if i use isopropyl alcohol as a coolant, will it dissolve the tubing?

 

Isoprophyl will damage any plexiglas in the loop.