Unconventional Liquid Cooling Discussion

[Callsign_Vega]

For my next build, I will be seeking another unconventional liquid cooling system. Various questions. Below or above the dew point? Above or below freezing? And always the thorn in the side of such projects: condensation prevention.

Planned system: i7 3960, X79, four 7970's. EK CPU, motherboard and GPU water blocks, Iwaki RD-30 pump.


Option 1:

Use the same sub-zero liquid cooling phase change system as my previous 990X/Quad 3GB 580 build from 2011 (link located in sig).

Pro's:
Will get sub-zero temps for great over clocking.
Dumps the heat outside during summer.
Dumps the heat inside during winter.
Less stress on home HVAC system to offset some of the cost.
Portable if I move.

Con's:
Uses quite a large amount of electricity.
It is loud outside the home.
Serious condensation prevention measures required.


Option 2:

Geothermal cooling loop/tank under ground next to house.

Pro's:
Temperature will not be sub-dew point, but will be much better than traditional indoor radiator water cooling.
Relatively constant temperature around ~10-15C if dug 8 foot deep.
Virtually maintenance free.
Dumps heat outside the home during summer.
Temperature of cooled computer parts should stay just above the dew-point, eliminating condensation prevention.
Very low energy use (just the pump which is required for any water cooled loop)

Con's:
Dumps the heat outside during winter.
Rental of digging/well drilling equipment is costly.
Initial labor requirement is vast.
Copper tube price is quite high.
Non-portable if I move.


Option 3:

Mineral Oil cooled with phase change down near sludge point. I have read mineral oil might become too thick to pump even as high a temperature as 10C. I will have to buy a bottle and do some viscosity tests. There is a computer out there that has run years in mineral oil without problems.

Pro's:
The need and cost for all water blocks is eliminated.
The need for condensation protection for sub dew-point operation is eliminated.
Heat can be dumped outside during summer.
Heat can be dumped inside during winter.
Less stress on home HVAC system to offset some of the cost.
Portable if I move.

Con's:
If mineral oil working temperature only goes as low as 10C, it might be a catch 22 seeing as that is around the point you don't need condensation protection anyway.
Cleaning of parts required for resale.
Unknown reaction to silicone, sometimes a key material used for waterproofing.
Uses quite a large amount of electricity used in conjunction with phase change.
It is loud outside the home.


Option 4:

Traditional indoor water cooling with a large radiator and fan such as from a truck/automobile.

Pros:
No need for condensation protection as going below ambient air temperature is impossible.
Heat is dumped inside during winter.
Simplicity
Low maintenance
Low cost
Least logistics involved and portable if I move.


Con's:
The best cooling possible will be around ~20C or whatever your indoor air temperature is at.
Temperature will fluctuate some as your HVAC system turns on and off to dissipate the heat.
The most stress on home HVAC system of any water cooling solution.
This setup would have the highest temperature delta between components at idle and max load.


Some other thoughts:

I've noticed with my last sub-zero build that I hit max safe voltages on components like the CPU and GPU's way before I even broke 10-15 deg C under 100% load on said components. My understanding is that once you hit a certain voltage on a 24/7 computer, no matter how cold you go the voltage can damage the components and/or seriously degrade their lifespan. So that begs the question, is it even necessary with today's components to cool below the dew point? If not, that alleviates the headache of condensation protection. This first came to light for me when some of the other top members were competing with me for the top benchmarks. They got within a few percentage points of my scores with ambient water (albeit they were some pretty hardcore ambient water setups). So is sub-ambient cooling even necessary besides the "wow" factor and the diminishing returns too great? Especially when you get into condensation prevention territory? Is it just too bad-ass to have 100% load CPU and GPU's operating at 7 deg C in a 24/7 setup?

As for if I did go with my original sub-zero cooling system. That brings up the condensation gremlin once more. Before I used Dragon Skin liquid curable rubber. It did prevent condensation but it was also difficult to work with. It had low surface tension and it settled into every low spot and did not coat vertical surfaces too well. It is also very difficult to remove. With that low of temperatures, thick layers of insulation under the dragon-skin were required yet condensation on the outside skin still developed.

Mineral oil would solve the condensation problem, but you get back to the low temperature viscosity problem. Does anyone have any thoughts/experience with mineral oil? I understand aquarium air pumps can be used to circulate the mineral oil over the surfaces of the hot components to great effect.

I've also thought about vacuum sealing. While it doesn't create a true 100% vacuum, it would eliminate most of the moisture. Finding bags, vacuum sealing equipment and a way to vacuum seal all of the connections would be a mighty project in itself.

That brings me to the simplest, cheapest and easiest implementation. An air tight container sealed off with silicone or the like with massive amounts of desiccant inside. This would alleviate any atmospheric pressure issues and the desiccant should drop the air moisture directly contacting the components to below 5%. Surely enough so that water droplets should not form causing shorts.

I will attempt to stay away from any direct surface type conformal coatings as the condensation on top of the coating would be severe at the temperature my last system operated at.

I appreciate any thoughts, suggestions and any experiences with the items in this topic.

[antiacid]

Interesting post. I've myself considered option 1-2-4 but I think you're spot on when you discuss the actual benefit of going below-ambient. I would ask a few more questions to help you refine your idea:
1- is operating cost an issue?
2- What is your workload? Gaming? 24/7 crunching? Setting OC WR then going out for a beer?
3- what kind of weather do you have? I've personally had to dig 3 tons of dirt to build a biodigester in tropical climate (let me tell you that rain + dirt = mud, mud + hole = lot's of re-digging) and I can tell you that shovelling that can take you a couple of weeks of part-time work. Then again, you'll get buffed
4- do you own your current home? Is it a situation where you'll stay there at least 3-5 more years? I would advise against geothermal if you're moving soon
5- Do you need heating in winter? The large radiators from trucks would fit that profile!
6- you mention loudness outside your home. Is that an issue for you/neighbors?
7- depending on how deep you go, the iwaki pump might not have enough head, you might need to adjust for that

Personally, I would go with a geothermal loop if I owned a house. I would dig it myself using as little tech as I can and I would setup my loop with a QDC or two and plug in a large radiator during winter inside the house for heating purposes. Sub-ambient to sub-zero zone is too much effort for too little reward (energy cost, coating, condensation, etc) while sub-zero is eventually really costly in electricity. Then again, my background is in bioresource engineering and closed-system growing of food so maybe my priorities aren't exactly the same as yours for this project

Good luck nonetheless, your previous worklog was quite interesting. I'm looking forward to your next build!

[gmat]

Instead of mineral oil (which has the shortcomings you mention) did you consider 3M Fluorinert ? I recall Cray used that for full immersion on some of their supercomputers, with chilled Fluorinert. It worked for them so it might work for you ?

[defect9]

isn't flourinert something like $200 a gallon though?

[antiacid]

fluorinert isn't exactly environmentally friendly, btw (http://en.wikipedia.org/wiki/Fluorinert)

[paulbagz]

If you're spending more then six grand on a system, I would of thought operating costs would be the least of your concerns.

-PB

[iboomalot]

I got an idea

take a 55 gallon drum of water and bury it with a large radiator inside and pipe it into the house.

The water would take a long time to heat and at night the system would chill.

be sure and use a steel drum so it exchanges to the ground effectively.

[gmat]

iboomalot: this is roughly the geothermal option, some people have done this already, and the OP is considering it (option 2 if you read his post..)

isn't flourinert something like $200 a gallon though?

Given the costs of his previous systems, i doubt the price is a concern.

[Callsign_Vega]

Interesting post. I've myself considered option 1-2-4 but I think you're spot on when you discuss the actual benefit of going below-ambient. I would ask a few more questions to help you refine your idea:
1- is operating cost an issue?
2- What is your workload? Gaming? 24/7 crunching? Setting OC WR then going out for a beer?
3- what kind of weather do you have? I've personally had to dig 3 tons of dirt to build a biodigester in tropical climate (let me tell you that rain + dirt = mud, mud + hole = lot's of re-digging) and I can tell you that shovelling that can take you a couple of weeks of part-time work. Then again, you'll get buffed
4- do you own your current home? Is it a situation where you'll stay there at least 3-5 more years? I would advise against geothermal if you're moving soon
5- Do you need heating in winter? The large radiators from trucks would fit that profile!
6- you mention loudness outside your home. Is that an issue for you/neighbors?
7- depending on how deep you go, the iwaki pump might not have enough head, you might need to adjust for that

Personally, I would go with a geothermal loop if I owned a house. I would dig it myself using as little tech as I can and I would setup my loop with a QDC or two and plug in a large radiator during winter inside the house for heating purposes. Sub-ambient to sub-zero zone is too much effort for too little reward (energy cost, coating, condensation, etc) while sub-zero is eventually really costly in electricity. Then again, my background is in bioresource engineering and closed-system growing of food so maybe my priorities aren't exactly the same as yours for this project

Good luck nonetheless, your previous worklog was quite interesting. I'm looking forward to your next build!

While operating cost is not a primary concern, it is a consideration none-the-less. This is strictly a gaming computer that would be used around 4-5 hours at a stint. I just use the phrase 24/7 as that rules out any benchmark only type cooling types such as LN2. I am in lower Alabama that gets very hot and humid for a good 7-8 months out of the year. I'd imagine eight foot underground the temperature is pretty cool and stable pretty much like anywhere else.

The ground is sandy and wet. I've heard of people drilling decent sized and depth holes simply with metal pipes and water. That would be interesting to look into seeing as vertical geothermal pipes can be quite effective. Heating in winter would be a bonus. Possibly like a switchable Y-valve to send the water either outdoors or in. The 15K BTU chilled water window cooler I have can be quite loud outside. Although my neighbor has never said anything, I do suspect he thinks I am crazy for installing a window A/C unit in a house with central HVAC.

I've read even with vertical geothermal pipes you don't need a super strong pump. If you were to solely bring water up as in a well setup you need a decent sized pump, but mine will be a close loop system. Gravity helping push down the water on one side of the loop helps with the suction up on the either side. Mainly interior tube wall friction is the largest power robber in a close loop system.

Instead of mineral oil (which has the shortcomings you mention) did you consider 3M Fluorinert ? I recall Cray used that for full immersion on some of their supercomputers, with chilled Fluorinert. It worked for them so it might work for you ?

Fluorinert is the stuff to use but it also costs $500-800 a gallon! I would need around eight gallons for my sub-zero setup. Could you imagine springing a leak on something that costs $19 an ounce? LOL

http://www.ebay.com/sch/i.html?_from...All-Categories

I got an idea

take a 55 gallon drum of water and bury it with a large radiator inside and pipe it into the house.

The water would take a long time to heat and at night the system would chill.

be sure and use a steel drum so it exchanges to the ground effectively.

I've read an online article about a guy that sank a converted propane tank for his cooling setup and it worked out quite well. His water temp only rose like 2 C after four hours of computer gaming. The problem with a large tank is you need a large hole in the ground. Not sure about renting the backhoe just yet!

I might be moving this year so I think any geothermal setup is out for now. Although once I get settled in, I think it will be my #1 project at my new house. In the interim with this next build, I might just go with a large indoor radiator setup until a move and can set up a geothermal loop. I might try and find a large automotive copper radiator with a 12v fan and work from there. Although I understand those might be hard to find seeing as most radiators are pure aluminum these days.

[stren]

Yes voltages will continue to be a problem in the long run with subzero cooling like you had on the last project so like you said you can save money and run closer to ambient for a minor performance hit. If you were going with a 8 core sb-e then it might be different however your money might be better spent cherry picking cpu's and gpus. There *will* be a performance hit though even if it's tiny as nearly every chip will overclock better at lower temps (assuming no walls due to design or bugs are limiting you).

If you're even thinking of moving soon I wouldn't bother digging a geothermal setup. For lower costs you could also consider a bong setup but you'll have to worry about a filtration system or mineral build up.

[antiacid]

Seeing as you're moving out soon-ish, option 2 is out.

However, if you feel like tinkering, you could mix option 1 and 4 together. You already have a sizable investment in cooling equipment and expertise on operating it. The way I see it, doing sub-zero for cpu is worth it but maybe dew point temperature might be enough for video cards/ram?

If you're really down for a project, you could build a "cool box" for your components (maybe using the output side of the sub-zero cpu water going through a radiator and fans to cool the air going in), instead of coating the board and running it in a warm room...

[Callsign_Vega]

Seeing as you're moving out soon-ish, option 2 is out.

However, if you feel like tinkering, you could mix option 1 and 4 together. You already have a sizable investment in cooling equipment and expertise on operating it. The way I see it, doing sub-zero for cpu is worth it but maybe dew point temperature might be enough for video cards/ram?

If you're really down for a project, you could build a "cool box" for your components (maybe using the output side of the sub-zero cpu water going through a radiator and fans to cool the air going in), instead of coating the board and running it in a warm room...

Can you elaborate? How to prevent condensation? Are you thinking of some sort of sealed cool box with desiccant in it or something?

[antiacid]

sorry for the delay, I've been held hostage at gunpoint while walking in on an armed robbery, made it out alright though.

The coldbox idea was that if you keep subzero on the cpu, insulation is minimal (so you won't have 2lbs of dragon skin to deal with) and the water coming out of the cpu block is still quite cold (I seem to remember you went -15 at the tank, so definitely under ambient room temperature which I'm going to guesstimate at 20c/68F). If you piped that cold water through a radiator+fan, you could manage to significantly cool the air around a small volume (so video cards + mobo). Now we're worried about condensation on your parts, so I went through Fort Rucker's almanach for the summer months and it seems it's a rather dry heat, which is good for this project. I'm going to assume you control humidity in your house since you discussed HVAC, so we can calculate that at 70%RH, saturation occurs at about 14c/58F and we can drop down to 2c/35F at 30%RH. Practically, this means that I don't think you'd even need dessicant in your cold box. The rest is what you said, a somewhat sealed box with the radiator/fan on one end. I'd also get creative with the piping, I wonder how that apogee HD would work out with your chiller...

[mlwood37]

isn't flourinert something like $200 a gallon though?

Nope can get it for £75 a ltr same as novac with is more environmental friendly and not a heavy.

[defect9]

damn, so its more like $450 a gallon. ouch.

higher if we're talking imperial gallons...

[Kayin]

Look for Midel 7030 then. Transformer oil. Some cheaper and safer than perfluorooctanes.

Oops, 7131, and here http://www.midel.com/

[Callsign_Vega]

sorry for the delay, I've been held hostage at gunpoint while walking in on an armed robbery, made it out alright though.

The coldbox idea was that if you keep subzero on the cpu, insulation is minimal (so you won't have 2lbs of dragon skin to deal with) and the water coming out of the cpu block is still quite cold (I seem to remember you went -15 at the tank, so definitely under ambient room temperature which I'm going to guesstimate at 20c/68F). If you piped that cold water through a radiator+fan, you could manage to significantly cool the air around a small volume (so video cards + mobo). Now we're worried about condensation on your parts, so I went through Fort Rucker's almanach for the summer months and it seems it's a rather dry heat, which is good for this project. I'm going to assume you control humidity in your house since you discussed HVAC, so we can calculate that at 70%RH, saturation occurs at about 14c/58F and we can drop down to 2c/35F at 30%RH. Practically, this means that I don't think you'd even need dessicant in your cold box. The rest is what you said, a somewhat sealed box with the radiator/fan on one end. I'd also get creative with the piping, I wonder how that apogee HD would work out with your chiller...

Hostage at gunpoint, are you serious? I didn't know Canada had crime. :|

The coldbox idea is interesting, I wouldn't even need to get water blocks for anything. ALl the GPU's etc could use their stock fans even with that cold of air being piped into a large radiator and fan setup. I definitely would have to seal it air tight which isn't that big of a deal if properly done. I could get a long radiator with like four fans blowing straight down on the 4 GPU's and CPU. This also has the added benefit of being able to cool all of the computer components even HDD's and CPU (actually not sure if I would put a mechanical HDD in that cold of temp but SSD'd should be ok)

I wonder what the temp difference in heat transfer would be like with stock air coolers in the chilled air setup would be instead of getting water blocks for everything and still using the air-tight/desiccant anti-condensation measure.

Although like you said, would going through all of that really have much of a benefit versus a good ambient water cooler setup. I think temporarily I might do the auto radiator type setup and then move to geo-thermal after I move into new house. Having ~10-15C water, low power use and the benefit of not having to deal with condensation protection seems like a great combo.

Look for Midel 7030 then. Transformer oil. Some cheaper and safer than perfluorooctanes.

Oops, 7131, and here http://www.midel.com/

I could not find any prices. Do you have an ballpark idea on the cost?

[crash5s]

fluorinert isn't exactly environmentally friendly, btw (http://en.wikipedia.org/wiki/Fluorinert)

Nor is chewing through mobo's and builds and all that toxic waste a few times a year and pouring anti-freeze down your drain but who cares? Trust me, with the power draw on some of the systems here "eco friendly" flew out the window and got shot dead.

[Church]

The newer houses/apartments are, more modern extras comes with them. If new houses eg. in japan may have fiber and alike stuff .. why not design one with geotermal loop in each as standard project with water inlets in wall just connect to?

[Callsign_Vega]

The newer houses/apartments are, more modern extras comes with them. If new houses eg. in japan may have fiber and alike stuff .. why not design one with geotermal loop in each as standard project with water inlets in wall just connect to?

Ya, if I was building a new house from scratch I'd put a serious geothermal loop under the foundation just for my computer. That would be so awesome. Plus a geothermal loop for helping the regular HVAC system.