Callsign_Vega
01-02-2012, 03:05 PM
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? :D
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.
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? :D
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.