Question about fridge cooling??

[Amd Man]

I'm gettin ready to do some coooling with a 1.8c fridge.. I plan on stuffing two radiators and res&pump into it..What I want to know is, how COLD will the water get????

I will be cooling a 225w Peltier...

The fridge also has a small freezer in it and I plan on leaving the freezer portion open soo that the whole fridge gets really cold.

Should I leave the pump&res out of the fridge or leave it in, my case will be on top of the fridge. I am using 1/2 silicone hoses, will I have to insulate the hoses? Also, my mobo is already insulated, I have the maze 3-1 wb, will I have to insulate the plexiglas portion of the waterblock?

Thanks for any help

[Amd Man]

Anyone??:(

[Player0]

Sorry AMD, been a long weekend here ;)

Hmm...how cold will the water get, well that greatly depends on your fridge and insulation. Your CPU and Pelt will be about 400-450w of heat, so your fridge will have to deal with that. The important thing is keeping the water in the fridge for as long as you can, so I would use at least 3 big radiators and some large fans on them. You shouldnt really hear them inside the fridge anyway. I would mount the radiators on the bottom since the cooler air will be there (which is why my fruit ends up frozen in my personal fridge :P)

As for how cold? No idea. Depends on how well this works. I doubt your water will freeze, so don't use too much antifreeze, just enough to stop algae growth (they seem to like colder water better).

I would put the resevoir right in the freezer section, as for pump, I'd mount that outside of the fridge, since you need one less hole (power cord). You want to seal up the wholes you make for the tubing.

You will want to insulate your silicone tubing, for sure. Did you get 3/4" thick? or just 5/8"?

I haven't had to insulate the plexi on my old Spir@l. My maze3 well, is all copper. It doesnt get very humid where I live usually, only on rare occasions, but...you might find you need to waterproof it. Either keep a close eye on it, or waterproof it and dont worry about it anymore. Usually better safe than sorry :)

[dicki]

hi mate good to see you on the boards :)

been a long weekend for me too but i'm here now ;)

i'll ditto everything player said but i will add something to watch out for... fridges are not designed to deal with a constant heat source... a constant heatsource will mean that the compressor will have to work harder and the life of the fridge will be reduced that much... keep a tight eye on temps and see if the compressor comes on much more frequently... if it does you may be in for some problems but either way it will definatly be interesting

dicki

[Amd Man]

Thanks for all of your replys:) I really want to make this work the first time as I really hate pulling everything apart over and over:D

The hose I have is the 1/2" ID 3/4" OD..(Danger Den)

So I should go with the cube radiators? like the Aqua Cube or Danger Dens Cube, instead of the Black Ice Radiators? I plan on putting the pump and res in the freezer section as it is one unit. Will I have to keep the pump on all the time soo that the water does not freeze? and will the cold temps in the fridge "hurt" the pump?

Do ya think that the fridge has enough to cool 400-450watts of heat? I figured that the water will stay in the area of just above freezing? but what the heck do I know???:D

[dicki]

yes you'll definatly need to keep your pump on all the time if the liquid freezes you'll have real troubles.

use a good quantity of anti freeze in your mixture, p0 or kode should be able to recommend a good mix for cold water

cold temperatures won't hurt the pump... condensation might... and the possibility of getting frozen chunks of stuff in the rotor might ... personally i'd mount the pump outside the fridge... it's one less heatsource for the fridge to worry about and theres no danger of condensation... use plenty of antifreexe in the system and leave the pump on nonstop.

using radiators in a fridge is ok but i'd be looking at a better form of heat transfer... air is an insulator so transferring heat to it is not really easy. metal -> metal transfers are far easier so i'd be thinking about some kind of custom heat exchanger for instance copper pipe wrapped around the cold element of the fridge or a large flat metal rad pressed up against it... if you can remove the heat by conduction everything will be far more efficient... and hopefully you'll get a big block of ice form round the heatexchanger that will aid cooling... just some thoughts...

dicki

[Player0]

Dicki is right of course, using the radiators in the fridge is not the best solution because of the air exchange. But, on the plus side of this, you will be less likely to get frozen water problems, and will be putting less strain on the fridge.

I suggest putting a large cooling fan on the back heat exchanger of the fridge, since most fridges do not use any sort of fans. This will help keep your temperatures down, and will make the fridge more efficient. The strain however will be there, if its an older fridge which already has a lot of hours, your going to really overwork that compressor. But, if your using air inside the fridge, well, that means less strain.

There are lots of other alternatives, like filling the fridge with water-mix, and dunking the radiators in that. Really, there are lots of things you can do, and I think you need to be proactive and figgure out the best solution for yourself :)

If you want to use preexisting parts, use your BI Xtremes in the bottom of the fridge with lots of fannage inside. Yes, your pump needs to be on all the time your CPU is on. Yes, this will help prevent freezing. No, the cold wont damage the pump, neither will condensation if its a submersable pump (most inline pumps are also submersable). Frozen water can damage the pump though, so make sure you get a thermometer in your tubing and make sure you add enough antifreeze to counteract any freezing. You will have to experiment with how cold it will get before determining. Add antifreeze in small doses, and do the mix math. You can determine the antifreeze-water ratio you need for a given temperature by reading the back of the antifreeze bottle. Too much antifreeze will be detrimental to your cooling.

You can probably get away witha 5% or 10% mix. Less antifreeze the better.

[Amd Man]

does my pump need to be on even when my puter is off???

[Player0]

No? Id recommend against that. But make sure to turn the fridge off too, or your lines might completely freeze, making turning it on again really hard :)

[Amd Man]

Well, if I turn the fridge off and on all the time, does that mean That i would have to wait for the fridge to get cool before each turn on or what? or just turn on frigde and system at the same time? How long does it take for a fridge to get cold?

I would be afraid that the heat from the peltier would not allow the fridge to get cold fast enough???

Soo what should I use? I have a Black Ice Extreme and a Aqua Coil Cooling Cube, Or should I just use both of them? Stick the two of them in series at the bottom of my fridge?

[dicki]

doh! i forgot inline pumps are water proof! wheres that dunce cap?

[WolfMan]

I have done some extreme cooling myself with a drinking cooler acting as a resivior/water chiller. My apartment is really humid so i insulated everything, Hoses, waterblock, socket etc. My guess at water temps were just above 0c. The amount of condensation was ungodly and in the end caused the demise of my XP1900 and my Purple Ray :( The condensation occured between my waterblock and cpu of all places and caused a major "grounding" of the mobo and cpu. In my humble opinion a fridge is really an eye sore not to mention inefficient. But good luck and for god sake Insulate everything!! :)

[Player0]

AMD Man, im afraid you are just going to have to experiment for yourself to find these answers :) Don't know how your fridge will react, since they all are quite different.

As for the radiators, more the better, always.

[LiquidRulez]

why dont you just gut the refrig. and make a nice water chiller? would be way more efficient than what the cold air in the fridge can do, considering the amount of heat in watts your sys. is putting out.

if i had a small fridge, thats what i would do.:D

[Amd Man]

I would love to do that but have no idea about the workings of a fridge as far as what is involved in taking it apart and then what to do once i get the compressor and condenser out?? and help would be appreciated:) I would like to build a chiller in this way but dont know what to do:)

[gamefan]

interms of the troubles that fridges have with running 24/7 what u can do is add thermal mass to the frdge, eg, if u have some metal bar stock stick it in the fridge in every availabl spot, it till remain colder much longer then air, even a jug of milk will help, or my favorite,beer, btw beer is optimal because it contains water which has one of the lowest absorbtion points of heat

[Hundekot]

as far as making a water chiller, it's pretty damn easy. since you have the cooling coil in the top of the fridge, you can probably work some slack into it. if you get a cheap bucket (square one like you used to keep crayons in back in kindergarten) us that as the resivior, and just dunk the whole evaporator in the cooling solution.

Also, these minifridges are made to cycle on and off. If you cut the wires in the back that go to the thermostat, and just rewire them directly to the compressor, it'll run as long as it's plugged in.
If it's gonna run 24/7, you also need something to cool the compressor, this is just a bunch of little snips of copper that I bent in half and A/S epoxy'd to the comp. Barely get's warm
I'm currently in the middle of building a dual fridge system, where i'll have a waterchiller as described above and another minifridge with the MB being cooled in the freezer.
I'll post everything here when I get it up and running.
Good luck
Hundekot

http://www.ptialaska.net/~carrion/block/hunds.jpg