Proper A/C Chilling (pics)

This is a chiller I made with a window air conditioner and a cooler to cool my aging socket 478 system. The temperature of the liquid in the reservoir after about an hour of running time is about -32C, at an ambient of about 20C and without load, other than the heat dump from the in-line pump.

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A/C unit: Sears Kenmore 5300 BTU (with remote control), modified as follows: Removed the plastic face and louvers. Removed the evaporator fan. Mounted the controls on the side of the unit. Placed the end of the temperature probe underneath the condenser. Attached rubber feet to the bottom of the unit, which raised it about three inches, to allow the evaporator to be placed down into the reservoir. Painted the housing red. Put a blue cold cathode inside the housing. Cut away some of the plastic inside the unit around the evaporator to give me some space to bend tubes and move the evaporator. Carefully bent the tubing to the evaporator to allow me to pull the evaporator about three inches forward, for placement in the reservoir.

Reservoir: Rubbermaid 13.2 qt slim cooler, modified as follows: Removed lid. Cut hinges off lid and cooler. Mounted ½ inch ID brass couplings through lid, sealed with 2-part epoxy. Filled interior of lid with expandable foam. Drilled hole and inserted thermometer through lid. Cut away small piece from back of reservoir to allow placement of evaporator in reservoir, and placed evaporator in reservoir. Trimmed this piece down to make space for the evaporator tubing, glued the piece back into place using expandable foam, and sealed with silicone. Attached clearflex tubing to brass fittings on inside of lid with hose clamps. Placed weather-stripping along lip of reservoir. Filled reservoir with coolant. Tightened lid down with cargo straps.

Coolant: About 1/3 anti-freeze and 2/3 denatured alcohol.

Tubing: ½ inch ID Tygon tubing, attached with hose clamps.

Pump: Danner Mag Supreme, model 3. The pump was disassembled, and reassembled with Devcon 250 used to seal all potential leaks. Devcon 250 was layered on the outside of the pump impeller housing to further prevent leaks and cracking. I think I should have used the model 2 pump: less flow but it also produces less heat.

Waterblocks: Swiftech cpu and gpu waterblocks. Each waterblock was disassembled. The base plate and block housing were sealed with Devcon 250. The plastic barbs were removed and replaced with ½ inch ID brass barbs, which were glued in place with Devcon 250.

Devcon 250 is an industrial adhesive. Its operating temperature is from -67F to 250F. It is not affected by high and low pH’s, and has a strength of 3,200 psi, according to the product datasheet. I found this stuff at J & M Industrial Supply online.

The total cost for this chiller was about $375.

Some things to remember: Devcon 250 is toxic, use in a well ventilated area. Denatured alcohol is flammable, and evaporates rapidly. Use in a well ventilated area, and make sure the finished chiller is sealed to prevent evaporation.

I have run the chiller for 24 hours with no leaks. I added some more silicon on the inside of the reservior around the evaporator tubing. I am going to let it run for another couple of days and check the coolant level to see if it is evaporating. The next step is to insulate the tubing, pump impeller housing, and the waterblocks. Then I will mount the blocks to the computer and start overclocking, benching, and playing Oblivion. I will update this thread when this project is complete.

Many thanks to XS and the users of this forum.

very nice :). great temps with a nice looking system. good work!

SwEeT:up:

Slap sum armaflax on dat!

Looks really nice , I plan on trying somthign liek this over the next few months

painting the AC unit made it look really nice

Yeah it did. That is some serious frost action there man. Sick :D

Yes the red did wonders over the other A/C's I have seen. Good job. Now get it ins. and see what it can do.

very clean looking nice work

Thanks for the compliments, they are much appreciated. It pains me to say this, but the compressor in the a/c unit is not turning on. This unit has run for a total of about 4 hours. The last time I ran it I *probably* short-cycled it twice, meaning, that I turned the a/c unit off and then on again without waiting 4-5 minutes in between. It ran fine, and then I shut it down for a couple of days. Now, the fan runs, the compressor is not turning on, by the sound of it, and it is not cooling. I have not yet removed the cover to get a close look at the compressor. Any suggestions?

Try shorting the thermostat altogether.

Gautam, thanks, that was the answer. I forgot the obvious fact that as the chiller is in my basement, and winter is approaching, the ambient temp in the basement is down to about 58 or 56F. The sears kenmore ac unit is designed to shut off when the temp probe reads 60F or lower. So the ambient had dropped below 60F since the last time I turned it on. I took the cover off, got the probe out, squeezed it in my hand for a few minutes to get it over 60F, turned it on and the compressor kicked in. I initially had it set up for inside use, so I put the thermostat under the condensor, thinking it would never drop below 60F in the house. The thermostat plugs into the circuit board with a 2 prong female plug. I'm going to solder a wire across the two male prongs, shorting out the thermostat. Thanks again.

The temperature probe is a bulb connected by 2 wires that plug into the circuit board. I cut off the bulb and soldered the two wires together, thereby removing the temp probe from the system. The a/c unit will now run continuously as long as it is powered up.

I didn't do this originally because I had planned to put this chiller inside (not in the basement) where ambient would never drop below 60F (the a/c unit's default shutoff temp). This thing is a beast though, big and loud, with the potential to leak/evaporate denatured alcohol (which is also flammable). So I think it will remain in the basement for a while longer.

I checked the fluid level in the reservoir, and the liquid does not appear to be evaporating.

I will update this thread periodically. I am insulating computer parts, and waiting for others to arrive. Progress will likely be slow, as I have only a couple hours a day at most to work on this.

Those frosted coolant lines look so good to me for some reason, just makes my day :)

Glad to hear you got it working, and since I didn't mention it before, that's gotta be the best Kenmore AC mod job I've seen, which is saying a lot since they're so ubiquitous. :p:

You probably have enough coolant to be able to run for several hours with subambient temps with the chiller off altogether. A bit of a headache, but personally I think its about the only way to achieve practicality whilst using a rotary compressor. Unless your ears are tougher than mine. :D

Quote:

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Originally Posted by Gautam

that's gotta be the best Kenmore AC mod job I've seen, which is saying a lot since they're so ubiquitous

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Thank you. Thats what I thought too, and I tried to convey that message with the thread title "proper" a/c chilling, without being too arrogant. I do think it was a good build, in terms of function and looks.

I began insulation tonight. I'm looking forward to overclocking with this thing.

ok, time for an update. I slapped some basic insulation on it to do some test runs, set the voltages, etc. So far, p4EE 3.2 @ 3.84, 240 fsb, with 2 Gb bh5 @ 1:1, 2-2-2-5. Here's the pics:

http://i74.photobucket.com/albums/i2...o/DSCN0106.jpg
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Cpu and socket: lapped the ihs with up to 2000 grit. put dielectric grease in and around cpu socket. used ceramique for thermal interface material.

Motherboard: asus p4c800-e. glued mousepads on back of motherboard with silicon. sealed the base of the agp slot with conformal coating, then put silicon around agp slot. put small heatsinks on clock generator and all mosfetts, mounted with arctic silver thermal adhesive. Did the vdroop and vdimm mods.

Waterblock: swiftech socket 478 block. removed plastic barbs, glued brass 1/2 id barbs in place using devcon 250. glued neoprene pieces to waterblock with silicon. used silicone and lubrex to fill in gaps.

Tubing: 1/2 id tygon. sleeved in foam pipe insulation, wrapped with foam pipe tape.

Coolant: I removed some coolant from the reservoir and added distilled water. The coolant mix is now about 1/2 denatured alcohol, 1/4 distilled water, and 1/4 antifreeze.

I ran the chiller, computer, and a prime 95 stress test at 3.84Ghz (240 fsb) for about 3 hours. Ambient was about 12C, and after about two hours the temperature of the coolant was about -32C.

I have a 4u case coming. Before I put this system in a case, I want to see if I can get 4GHz stable. I need to get to 250 fsb. My memory is holding me back, only because my max vdimm right now is 3.2v. I have done the vdimm mod, and it works properly. I need to redo the 3.3v sense volt mod on the power supply, I knocked it loose and the max 3.3 rail output is back to stock (around 3.2-3.3v). Once I redo the psu mod, I will be able to run my bh5 at 3.4 - 3.5v. This will hopefully allow me to get the fsb up to 250 1:1. When I put this system in its case, I will redo the ugly insulation job you see here. I will also remove the heatspreaders on the second pair of dimms. The video card used was a basic card for test purposes. I am insulating my x850, it will be in the loop also.

Edit: I guess my sig is obsolete now.

I reworked the power supply vmod, and I did the "universal vdimm mod" by connecting the 3.3v power connector pin to the vdd pin, got me another .1v vdimm. It looks like I'm stuck at 245 fsb for 1:1 stable (3.2 @ 3.92). I got the case in this weekend. Will be working on case pimping and video card insulation and testing. Hopefully I can finish this project in the next two or three weeks. Will update with pics then. A little optimistic with the video card in sig, but hey, it worked at those speeds watercooled...

Your card should pull into the high 600's or low 700's for core speed...I had an X850XT AGP breaking 720 using the exact same Kenmore A/C. :p: I suggest around 1.85v for such temperatures.

In the immortal words of Borat, "Varry Naice" ;)

Thank you. Yes, I'm looking forward to pushing the x850, the volt mods were easy, and it overclocks well on water.

Small update: I re-worked the psu vmod again, as per hellfire's guide in the XS vmods forum. Turns out I had the vr sense wire soldered to the wrong side of the fixed resistor. Now I can run the 3.3 rail up to at least 3.7v. I'm keeping it at slightly above 3.6v, which gives me slightly over 3.5v vdimm. I haven't tested it yet, but I think I can get to 250 fsb 1:1 now (4GHz). Started case painting etc too. Got some work deadlines coming up, so I won't really get into finishing this build until later this month. Will update then...

Killer rig!

sweet setup man! how much would it cost to replicate?

the total cost of the chiller, not counting the computer hardware, was about $375 US.

Have you considered migrating to a Dothan setup? Read someone said they weren't
very expensive at Ebay and as you may know, they rock :D

Was forgetting: congrats for the build :toast: Looks really sharp :cool:

update + pics. I decided that I needed another test run before I put it in the case to make sure everything is ready. (and the case isn't ready, and I wanted to play Oblivion).

For Oblivion, this system is running at 3.84 GHz (240 fsb 1:1). At 245 fsb I was getting the occasional ctd in Olbivion, so I lowered it to 240, where it appears stable after about 3 hours of Oblivion.

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After about an hour of game time, the temperature of the coolant was about -28C. I put the fan on to help control condensation, I think the fan raised the temperature of the coolant about 3C. This fan puts out massive cfm even on low. After about three hours of game time and the fan running, the temp of the coolant was about -25C.

A single layer of silicone and neoprene on the cpu block is not enough. The outside of it is getting cold, and condensation is starting to form. I will add a second layer of silicone and neoprene to the cpu waterblock.

I ran this test with a stock 6800 ultra. I think I'm going to use this card in the chilled system, instead of the x850. I will need to mod the bios, vmod the card, put some ramsinks on, and insulate the card.

THe 4U case is almost ready. I need to wait until WalMart restocks the "grabber green" engine paint, so I can give the inside of the case another couple of coats of paint.

Amazing how no extensive modification was needed for the unit.

very nice unit you have there

love the frost shots

is the 6800 ultra going shame you x850 clocked so bad
my x800xtpe does 660 640 on pencil mods

Those lines should be insulated better. Should help with temperatures a bit.

Another pic. Thanks. Yes the lines need better/cleaner insulation. The previous insulation job was a quickie for test run purposes. The a/c chiller itself was easy to build, it didn't take very long. The long part has been the computer build, which is still ongoing. I still have the x850, which I will swap in once I am done playing with this 6800u. I like sm 3 in Oblivion, I think it looks better. I was hoping to mount the case on top of the chiller, as in the previous pic, but it is too difficult to get the lines filled. Once I swap in the x850 in I can insulate the lines and be done.

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super looking dude!!!

:up:

Thanks for the compliments. This is as far as I'm going to get with this project for now. I've got some new hardware that I've having more fun with (and getting better fps in Oblivion with). This thing is going to stay in the basement on the workbench. I'm not sure its civilized enough to bring upstairs, where small children and domestic animals run rampant.

An update to the build thread: I replaced the cpu block with an Apogee, and built up layers of neoprene and dielectric grease around the block.

http://i74.photobucket.com/albums/i2...o/CIMG0024.jpg
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I got it into a daily working configuration.

http://i74.photobucket.com/albums/i2...o/CIMG0032.jpg

Very efficient CPU insulation, but I'd be worried about using the Apogee with the temps you're pulling; I've heard stories of Apogees snapping under mounting pressure at -30*C.