Practicality of chilling a mineral oil PC or vacuum chamber.

Freshchips · December 17, 2022

Hello all,

I am an HVAC technician and had an idea, now I am curious of any obvious flaws and the practicality of it. If you took a mineral oil cooled PC and used a chiller like in cooling threadripper video and used it to remove heat from from the mineral oil you could theoretically get the medium down to -20C or the freezing point of mineral oil. This would have a couple benefits for sub zero the obvious being that you wont be battling condensation as the whole PC is submerged. Also every component on the board would be at that tempurature so potentially power delivery could be more stable (I'm assuming) so overclocking should be easier at steadier voltages since VRMs remain cold. The only thing I'm questioning is would you still be limited at -20C?

The Other option would be to build a vacuum chamber that you could build the PC into but have an external chamber that you could add liquid nitrogen into to cool just the CPU. The obvious problem with this is there would be no air to cool off VRMs and other components. The solution would once the air and moisture has been removed you could replace the medium with medical nitrogen that will not have any moisture to remove the biggest fear of condensation. With the chamber having liquid nitrogen added as well and fans internally circulating the nitrogen you should be cooling off the medium passively so the nitrogen becoming stale should not be an issue as the chamber will act as a heat exchanger. Ill include two crudely drawn diagrams to try to explain my thought if it isn't clear. Again I'm not sure the practicality of either these ideas but I thought it was a fun thought experiment using stuff I have seen in my field.

fonzz1e · December 18, 2022

IMO the cost involved is too high for most users

vsteel · December 18, 2022

18 hours ago, Freshchips said:

Hello all,

I am an HVAC technician and had an idea, now I am curious of any obvious flaws and the practicality of it. If you took a mineral oil cooled PC and used a chiller like in cooling threadripper video and used it to remove heat from from the mineral oil you could theoretically get the medium down to -20C or the freezing point of mineral oil. This would have a couple benefits for sub zero the obvious being that you wont be battling condensation as the whole PC is submerged. Also every component on the board would be at that tempurature so potentially power delivery could be more stable (I'm assuming) so overclocking should be easier at steadier voltages since VRMs remain cold. The only thing I'm questioning is would you still be limited at -20C?

The Other option would be to build a vacuum chamber that you could build the PC into but have an external chamber that you could add liquid nitrogen into to cool just the CPU. The obvious problem with this is there would be no air to cool off VRMs and other components. The solution would once the air and moisture has been removed you could replace the medium with medical nitrogen that will not have any moisture to remove the biggest fear of condensation. With the chamber having liquid nitrogen added as well and fans internally circulating the nitrogen you should be cooling off the medium passively so the nitrogen becoming stale should not be an issue as the chamber will act as a heat exchanger. Ill include two crudely drawn diagrams to try to explain my thought if it isn't clear. Again I'm not sure the practicality of either these ideas but I thought it was a fun thought experiment using stuff I have seen in my field.

Mineral oil you would need to look at the viscosity chart to find out when it becomes too thick to do a good job. Before it becomes a solid it will be like cold honey. While your chiller is doing a great job of removing heat, places around the CPU are going to be overheating because they might be cooking the oil but since the rest of the oil is so thick it isn't circulating very well or maybe not at all. Basically you won't be cooling very well.

The cooler needed for the mineral oil system is going to be sucking power like no tomorrow. You might calculate you need to remove 800 watts from your computer, but then you also need to take into account the heat that is trying to come into your system. Because of the size and depending on how well you insulate the entire thing, you could be looking at 2 or 3 times the watts you would need to remove from the system. Don't underestimate that, running parts cold takes way more power than just what is in the system and it is very significant.

Vacuum box, very hard to make with a good seal and if you get down to a low pressure you could pop some parts. If there is any tiny amount of air in the chip it would be possible to crack die.

LN2 you could do and fill your chamber with CDA (clean dry air) or pure N2 without any water in it. Though you will need a lot of LN2 which will be costly and you will need to make sure you have a heater for your vent of the box. Because the nitrogen coming out of there is going to be so cold it will form an ice ball when it hits the moist room air unless you can get it above freezing.

Source: I work in an industry where one of my jobs is cooling chips in various ways. It costs A LOT of money to keep chips cold unless you live in a northern climate and run a liquid cool machine and have the radiator outside so you can have the -40F air remove the heat or have an air cooled machine in an unheated garage in the winter. Though keep in mind chips will also fail to work at cold temps just like they do if it gets too hot. Just because you can get something really cold doesn't mean that it will work.

Demonic Donut · December 27, 2022

Some components need to be warm(ish) to operate properly. RAM doesn't like getting sub zero. SSDs need to be warm to operate best. There's a reason that extreme overclockers only cool the GPU and CPU dies.

If you want a project try water cooling with a chiller. An appropriate glycol mix would get you sub zero easily enough.

Or even more exotic, do a DX evaporator for your CPU and potentially GPU. I've gathered everything I need for this except a working compressor but other projects always take over.

These are expensive to build and take a lot of electricity to run, but for the lolz they are very cool. Definitely not an everyday item.

More practical fun projects would be an evaporative fluid cooler mounted outside or a geothermal loop. You'll stay plenty cool with room for OC, keep the heat outside (if you want that in the summer etc) and still have a fun project.

But nothing beats liquid nitrogen for extreme OC, it's actually relatively inexpensive to get set up with liquid nitrogen and a pot for it.