Question using mineral oil

[rightchea]

So I notice that people are dipping their internal PC into a fish tank and not using reservoir and tubs. is that because the tubs corrode faster in mineral oil or it just the cool thing to do

 

[rubix_1011]

Here we go again.

So I notice that people are dipping their internal PC into a fish tank

No, not many people are doing this.

is that because the tubs corrode faster in mineral oil

Technically, tubing could possibly break down in mineral oil (although, more likely over the course of many, many years)...as does thermal compound, which does dissolve/break down more quickly, depending on formula. But no, this isn't the reason tubing isn't used, the reason is due to the volume of mineral oil absorbing thermal load, but doing so rather ineffectively. It is the same idea that when you go swimming, you don't use tubing to pump water around your body because your entire body is immersed in a fluid that is supposed to be lower than your operating body temperature.

Generalized Watercooling Theory


Watercooling is based on the set of principles that water is proportionally better than air to conduct heat away from a heat source based on conduction, or the direct contact of a heated source and a cooling source to transfer heat energy rather than convection, otherwise known as thermal conductivity. The ability of a substance to directly absorb heat energy is considered it's specific heat; in this case, the ability of heat directly absorbed by water and the required energy to raise overall temperatures by 1°C. While convection takes place with normal air coolers to provide the ability for air to absorb dissipated heat from the cooler, watercooling also employs this concept to some degree. Once the water absorbs heat energy via conduction from the blocks, it then transfers that through tubing to radiators cooled by fans. The difference is that a larger amount of heat energy is able to be absorbed and moved at any given time with a water loop due to pump flow forcing turbulent water through the radiator tubes while the radiator provides greater surface area to conduct heat energy from the water to the radiator and then into the air. The process is more efficient at transferring, displacing and dissipating excess heat energy based on the delta-T of the loop design. In short, the ability of water's excellent specific heat allow it to absorb heat much more quickly and efficiently from a source of heat (as well as also dissipating that heat back to a cooling source for dissipation) so it can also transport far more of that absorbed energy due to the thermal capacity of it as a medium away from heat sources to be expelled elsewhere.


Thermal Conductivity of Common Cooling Mediums (@~20°C; W/mK)
Higher values are better

Water...............................................0.610
Mineral Oil........................................0.162
Alcohol(Ethyl, Isopropyl, Buytl)...........0.161-0.200
Ethylene Glycol..................................0.258
Air...................................................0.0257


Specific Heat of Common Cooling Mediums (@~20°C;kJ/kg.K)
Higher values are better

Water...............................................4.19
Air...................................................1.00
Mineral Oil........................................1.67
Copper.............................................0.093
Ethylene glycol..................................2.36


There are a lot of discussions around mineral oil submersion cooling, and while this is a watercooling forum, it often gets brought up as a topic. That being said, here is a link to a maintained index of mineral oil discussions that either have originated in this forum or referenced as one of those discussions.

https://forums.tomshardware.com/threads/mineral-oil-q-a-links.332211/

 

[BFG-9000]

Ever notice those giant cylindrical cans on telephone poles? They are filled with mineral oil now because that is cheap, reasonably resistant to high temperatures and electrically nonconductive. But transformers in mineral oil are less reliable than what they used to use--PCBs, which have both higher thermal conductivity and a higher flash point, but became illegal to manufacture back in 1979.

Oil is fine for cooling things like that, but does a poor job on very concentrated heat sources where you would need both 4x the flow rate as well as 4x as much of it to cool as well as water. So yes you could immerse a PC (except HDD) into oil but would need some powerful pumps to cool it adequately--convection alone won't do it for sure.

You know what's far less messy? Air also has pretty poor thermal conductivity and is nonconductive, but you can sure pump a lot of it through a heatsink. Even though you'd need 6x as much of it to match oil, the price is even lower--it's free.

 

[rubix_1011]

Yes, transformers have been filled with oil for quite some time. Also, I would be willing to bet that the acceptable thermal limit for a power transformer is much higher than that than would be acceptable for PC components. We are also discussing a component that does really only one thing: distribution and load management of electrical currents vs. a complex computational machine.

There are a few issues with using oil submersion: hot spots (without any flow), dissipating heat without a heat exchanger (surface area vs. thermal load) and the slow absorption of thermal and lower overall potential of thermal loads into oils compared to that of water (thermal conductivity and specific heat).

There is a reason why vehicle engines circulate water/coolant as part of the cooling system rather than mineral oil, although engine oil does act primarily to move thermal load away from friction and detonation areas to expel thermal load into the coolant channel. Without oil, an engine would overheat from friction and seize up, while being unable to adequately transfer thermal load to the cooling medium...much like thermal paste does between a CPU (engine) and the CPU cooler. It isn't a 100% accurate analogy, but it does work.

 

[rightchea]

yeah I already have a air cooling computer system but I was trying to figure out how to get the temperature down on my PC by like 5 to 10%. It seems like getting mineral oil would be a waste of time/wouldn't make sense when using a system from fluidgaming.com.

BFG-9000, you are right about it being free but I live in a very warm climate and my computer never get under 75C when I am gaming. Even in the winter my computer is at 72 - 75C which is crazy. Probably need a case with better air flow most likely but not really trying to spend more than $100 - $150 on a case eithe, since I will be doing a full rebuild and giving my old computer to my wife since she is trying to start her own business.

 

[rubix_1011]

What is the ambient room temperature where the PC operates?

The issue seems more like airflow and build than actually cooling, but curious as to more detail.

Can you provide build specs, games played or software used to create load as well as room temperatures in both winter and summer?

 

[BFG-9000]

A custom watercooling loop is the most effective, but expensive. BIG air cooling is the most cost-effective and surprisingly can be quieter than the high-static-pressure fans used with radiators. But by far the cheapest is just using higher airflow fans--it's noisy, but works. You need 24x as much air to match watercooling, but have to admit a 250mph electric leaf blower sure isn't going to let your CPU reach 75C. Probably not much louder than the screaming Delta fans we used 20 years ago either.

Having had a number of air-cooled cars, I can report just air & oil works fine, but the charge is more likely to detonate with forced induction so limits how much boost you can run. Even after antifreeze was invented 100 years ago, finally allowing water-cooling in supercharged airplanes (it's cold at high altitude), our military continued to prefer air-cooling and gallons of mineral oil in radial engines until the Jet age after WW2!

 

[rightchea]

The house that I live in is 1900 sq ft, the room the PC is in is like 11x12 so it not that large and I live in GA So in the summers it extremely hot at times. games I have been playing are Ghost Recon, Star Citizen and some shooters.

PC Spec:
AMD Ryzen 7 1700 w/ Wraith heatsink
Sapphire RX580 8GB
16GB RAM
DeepcoolKendomen 5 fan case

The biggest problem is the only room available for the PC has three windows in it and even with the blinds close the heat is crazy sometimes.

 

[TJ Hooker]

BFG-9000, you are right about it being free but I live in a very warm climate and my computer never get under 75C when I am gaming. Even in the winter my computer is at 72 - 75C which is crazy.

So the temperatures of your CPU and GPU are in the high 70s while gaming? That's totally fine.

 

[rubix_1011]

Unless you are running something like chilled liquid or a compressor (or liquid nitrogen or dry ice) you cannot ever cool to room temperature or below**. Also, due to ambient room temperature, your idle and load temperatures will increase and decrease as a delta of ambient temps...just how it works.

And no, LN2 or dry ice are not meant for everyday use. Chilled watercooling and compressor chillers can be, but that's a few rungs above normal liquid or air cooling. It takes a lot of extra consideration and a whole bunch of DIY engineering. You'll want to get past Watercooling 101, 201 and 301 before you step into that arena.

** Edit, I suppose you can with other methods such as house water line or deep well systems, but those are very wasteful of fresh water. Easy Joe User method would be watercooling and radiator in an ice bath.