A/C to Chiller conversion

[Drewmeister]

I felt I should start a thread on my project due to all the interest I see in the A/C chillers & (cough)minifridge modding. I chose the A/C for its ability to dissipate large heat loads(CPU,GPU & Chipset) while maintaining low temps 24/7. They are also cheap, even a new one(5200BTU/$79-$98). The unit I'm modding is a GE 5200 BTU Room A/C-Digital Thermostat w/remote control. Model #ASW05LB. I bought it at Walmart last Friday for $98. There is a stripped down version for $79 but should do fine. They also had a 5150 BTU for $69 but were physically much smaller for 50 BTU less. Here are some quick dimensions: W16.75" H12.5" D12.5"/530watts~2cents/hr. Noise Level= less than a 92mm Tornado. I'll start off with some stock pictures.
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AMD Rig
2500XP-M/L12mod @ 228x11.5 2622MHz @ 2.06v-SLK900A/ 92mm Tornado
Abit NF7-S 2.0
2x256MB Corsair XMS PC3500 1:1 @ 5222 3v
ATI Radeon 9700Pro @ 400/355 Dynatron copper HS/ramsinks
3D MARK 2001: 20581

[Drewmeister]

Right out of the box free air the unit pulled to 1.66c and -5.55c with some cold air recirculated but would ice the evap coil. Also the thermostat sensor needed to be moved out of the way or else it will cycle the compressor at 62F- 64F. The lead on the sensor wasn't long enough to escape the chill so I just put a heating pad on it. I wanted to know how low this thing could go so I boxed the front of the unit and sealed it good with duct tape. This would create a freezer like environment preventing moisture from icing up the evap. The cold dry air would just keep recirculating til it reached its lowest temp. I use 2 Radio Shack digital thermostats for all the tests. Temps are evap out/ambient on the dual display and evap in on the single. With room temp at approx 72F it pulled down to -20c in approx 20min. Note it pulled down to -18c in 10min. Imagine sticking a radiator or two on the inlet or discharge of this puppy.
_______
AMD Rig
2500XP-M/L12mod @ 228x11.5 2622MHz @ 2.06v-SLK900A/ 92mm Tornado
Abit NF7-S 2.0
2x256MB Corsair XMS PC3500 1:1 @ 5222 3v
ATI Radeon 9700Pro @ 400/355 Dynatron copper HS/ramsinks
3D MARK 2001: 20581

[Drewmeister]

-20c is great and all especially for an A/C but this is an unloaded temp. I want my load temps to be around -20c +/- 5c so I needed quite a few more degrees. I decided to run it without any airflow across the evap to try to get it even lower. I measured the evap coil temp and evap suction temp . The thermistors needed alot of insulation for this test. With this last test it was able to pull down to -27c. Actually after I took the last pic the temp was at -27.3c and going down slowly I am completely satisfied with these results and will continue to with next procedure(goodbye A/C hello chiller). Next I will be putting the evap into a reservoir(12 can beer cooler or such). I will hunt one down today. From the looks of the suction and capilary tube it shouldn't be much trouble. With the right mixture of winter grade prestone and denatured alcohol I hope to hit -30c to -40c. I will keep you guys posted. If you have any questions or suggestions please fire away.
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AMD Rig
2500XP-M/L12mod @ 228x11.5 2622MHz @ 2.06v-SLK900A/ 92mm Tornado
Abit NF7-S 2.0
2x256MB Corsair XMS PC3500 1:1 @ 5222 3v
ATI Radeon 9700Pro @ 400/355 Dynatron copper HS/ramsinks
3D MARK 2001: 20581

[AngryAlpaca]

Looking good! Looking for -20C loaded may be a bit much, but it's worth a try.

[wasdiscovered]

I would suggest dumping the heating pad. Cut off the sensor then splice the two wires together. This gives the circuit zero resistance which allows the compressor to run continuously. Later on you can reinstall the sensor into the circuit along with another simple circuit in order to regulate the temps you run.

If you are going to use the Rubbermaid 12 can slim line cooler be sure to check that everything will fit in it. If you are going to use a submersible pump make sure it will fit because many of them will not.

edit:
I forgot to say that if you cut the sensor off as I suggested leave as much of the wire as you can on the sensor side. If reinstalled later on you don't want to have splices in your resevoir as the sensor will be submerged.

[Drewmeister]

The heating pad was just a temp fix to see how low I could get it without chopping anything up just in case I was to return it. I will be adding an external thermostat for better control but splicing the probe wires together like what wasdiscovered recommended will do fine if you want the compressor to run continuously. The stock thermostat only goes down to 64F. Wasdiscovered I just picked up the cooler and I see what you mean. It looks very tight in there. It starts out at 4.25" and narrows to 3.375" at the bottom. Width wise is 17.25" & 15.875" respectivly. This cooler has worked for alot of other people with smaller evaps and diff brazed connections. I will try to find another one. The suction loop is 4.5" wide, too wide for the slim cooler. I think I can just swing the suction line forward and into a wider cooler after I cut some of the evap partition away. Check out the photo. Also I ran one quick test with the coil submerged in about 1"-1.5" of denatured alky with hardly any insulation and managed -30c in 10 min and -34.2c in 20 min. I'm hoping it will break -40c fully submerged in a cooler. I feel like I'm OC'n an A/C.
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AMD Rig
2500XP-M/L12mod @ 228x11.5 2622MHz @ 2.06v-SLK900A/ 92mm Tornado
Abit NF7-S 2.0
2x256MB Corsair XMS PC3500 1:1 @ 5222 3v
ATI Radeon 9700Pro @ 400/355 Dynatron copper HS/ramsinks
3D MARK 2001: 20581

[edain]

may i ask whats makin all the noise in that a/c unit?

[Drewmeister]

Originally Posted by edain

may i ask whats makin all the noise in that a/c unit?

The A/C unit isn't quite as loud as my 92mm Vantec Tornado. The loudest part of the unit is the 10" condenser fan, which I run at low speed. The compressor quiets down some after a few minutes but still emits a little bit of a buzzing sound. The noise level can be greatly reduced by glueing some thin sound deadening material(insulation)on the inside of the cover and creating insulated intake chambers to surround the top and side vents.
_______
AMD Rig
2500XP-M/L12mod @ 228x11.5 2622MHz @ 2.06v-SLK900A/ 92mm Tornado
Abit NF7-S 2.0
2x256MB Corsair XMS PC3500 1:1 @ 5222 3v
ATI Radeon 9700Pro @ 400/355 Dynatron copper HS/ramsinks
3D MARK 2001: 20581

[wasdiscovered]

Finding a good reservoir can take a lot of searching. If it's to big it will take a lot of fluid and if it's to small then things will not fit. There's another way of going about it though. Simply get one that is big enough to hold everything you plan to use. Forget about trying to get something small. Get the biggest one it takes.

After you have everything set up simply replace the undesired space inside the reservoir with something else. I use bricks sealed in plastic. This way you are in total control of the amount of fluid your system uses. It also gives you the ability to experiment with different fluid levels. Another benefit is that if you decide to add more pumps in the future you will have the room.

I feel like I'm OC'n an A/C.

Not yet, that would be when you start playing with the refrigerant charge but that comes in much later.

[Drewmeister]

Ok watercooling guys... I'm going to need some recommendations for a pump and waterblocks(1/2'ftg) for the GPU(9800pro) & chipset(NF7-S rev2). I will use a WW block 1/2'ftg for the CPU. The pump will need extra flowrate because of the extreme temps. I will probably go with an external because of the heat factor. The pump absolutely must not leak! Also I would like to keep the prices of the blocks each under $50 and the pump under $125. What do you guys think of the Danner Pondmaster 700GPH Mag-drive for $96? http://www.shopping.com/xDN-Garden-pond_pump--qvc~V-
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AMD Rig
2500XP-M/L12mod @ 228x11.5 2622MHz @ 2.06v-SLK900A/ 92mm Tornado
Abit NF7-S 2.0
2x256MB Corsair XMS PC3500 1:1 @ 5222 3v
ATI Radeon 9700Pro @ 400/355 Dynatron copper HS/ramsinks
3D MARK 2001: 20581

[AngryAlpaca]

**** the chipset. Make sure you get metal tops. Why do you need extra flowrate? Just grab a Mag 3. Oh... If it must not leak, go with an Eheim or something. Get mags for less than a ridiculously stupid price at: http://www.aquatictech.com/pumps.html

[Drewmeister]

I have a plastic toolbox that almost fit the bill. My evap is 8.25" H but the max fill level of the toolbox is 7.75"(but would be dangerously close to the edge). Ideally I will need a reservoir with a 10" H edge to fully submerge the evap and so the suction line will swing right over and into it. I will keep searching for something like this(tool or fishing tackle boxes) or a larger cooler like wasdiscovered mentioned. Have a couple of pics of the toolbox idea. I would use at least 3/4" insulation all around it. There's a piece of it in the pics.
_______
AMD Rig
2500XP-M/L12mod @ 228x11.5 2622MHz @ 2.06v-SLK900A/ 92mm Tornado
Abit NF7-S 2.0
2x256MB Corsair XMS PC3500 1:1 @ 5222 3v
ATI Radeon 9700Pro @ 400/355 Dynatron copper HS/ramsinks
3D MARK 2001: 20581

[BigMoose]

Why don't you want to submerge the pump, will any damage take place or anything like that? Or is it just a precautionary measure?

[Drewmeister]

Originally Posted by AngryAlpaca

**** the chipset. Make sure you get metal tops. Why do you need extra flowrate? Just grab a Mag 3. Oh... If it must not leak, go with an Eheim or something. Get mags for less than a ridiculously stupid price at: http://www.aquatictech.com/pumps.html

I'm not sure what ratio of DEX-COOL/Alky I'll be using. I know the lower temps thicken the antifreeze and greatly reduce the pump output so I just wanted something with a little extra flow to compensate for that. What percentage of Alky would you recommend? I rather use a Mag 3 cause @ 35watts I would just submerge it then. Thanks for the link. Those are some pretty sick prices.
_______
AMD Rig
2500XP-M/L12mod @ 228x11.5 2622MHz @ 2.06v-SLK900A/ 92mm Tornado
Abit NF7-S 2.0
2x256MB Corsair XMS PC3500 1:1 @ 5222 3v
ATI Radeon 9700Pro @ 400/355 Dynatron copper HS/ramsinks
3D MARK 2001: 20581

[Drewmeister]

Originally Posted by BigMoose

Why don't you want to submerge the pump, will any damage take place or anything like that? Or is it just a precautionary measure?

I was just mainly concerned about the heat dissipation of the pump. Being submerged just adds more heat the cooling system has to get rid of. It is safe to submerge as long as the pump is designed for it. I may use the Mag 3 as a submersible because it only dissipates 35watts. 35watts will soak up approx. 119BTU. A 5200 BTU A/C may only be 800-1500 BTU at -25c(my guesstimate according to graingers cond unit specs of equal capacity). So anything more than that I would probably put inline.
_______
AMD Rig
2500XP-M/L12mod @ 228x11.5 2622MHz @ 2.06v-SLK900A/ 92mm Tornado
Abit NF7-S 2.0
2x256MB Corsair XMS PC3500 1:1 @ 5222 3v
ATI Radeon 9700Pro @ 400/355 Dynatron copper HS/ramsinks
3D MARK 2001: 20581

[Lando95]

Originally Posted by AngryAlpaca

**** the chipset. Make sure you get metal tops. Why do you need extra flowrate? Just grab a Mag 3. Oh... If it must not leak, go with an Eheim or something. Get mags for less than a ridiculously stupid price at: http://www.aquatictech.com/pumps.html

Nice link, thx.

[AngryAlpaca]

You keep adding alcohol until the water doesn't freeze. Or, you can find the freezing point of alcohol and work it out.

[Lumo]

Looks good Drewmeister, what gasses do those units run on?

[Drewmeister]

Originally Posted by Lumo

Looks good Drewmeister, what gasses do those units run on?

Thankyou...I'm not sure what other A/C units use but mine uses R-22. Although I just bought mine a week ago as you can see on the production tag it was manufactured in 12/02. Maybe I lucked out!
_______
AMD Rig
2500XP-M/L12mod @ 228x11.5 2622MHz @ 2.06v-SLK900A/ 92mm Tornado
Abit NF7-S 2.0
2x256MB Corsair XMS PC3500 1:1 @ 5222 3v
ATI Radeon 9700Pro @ 400/355 Dynatron copper HS/ramsinks
3D MARK 2001: 20581

[Drewmeister]

Originally Posted by AngryAlpaca

You keep adding alcohol until the water doesn't freeze. Or, you can find the freezing point of alcohol and work it out.

Pure Denatured Alcohol freezes at -90c so I was going to use 80-90% alky to 20-10% DEX-COOL to add some anti-corrosion properties. Water may corrode
the galvanized steel end plates.
_______
AMD Rig
2500XP-M/L12mod @ 228x11.5 2622MHz @ 2.06v-SLK900A/ 92mm Tornado
Abit NF7-S 2.0
2x256MB Corsair XMS PC3500 1:1 @ 5222 3v
ATI Radeon 9700Pro @ 400/355 Dynatron copper HS/ramsinks
3D MARK 2001: 20581