# Immersion Cooling Project



## billbartuska

You are aware that this stuff is flammable?


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## Tellik

EDIT2: It's not complete, but it'll take some more research. https://docs.google.com/spreadsheets/d/142ms5DROTb_amCmHY8VBQ2kdY_Zz9u4nyFobxLPNY0A/edit?usp=sharing

EDIT: This kind of answers some points below, and invalidates a lot of the information. I completely missed a specific part in the SDS for that fluid where the flash point is -6C. Based on that, I'm analyzing other fluid types in the Therminol line, such as ADX-10 (Which has a flash point of 136C.). Because of this, I'm going to need to take a close look at this information and come up with various safety margins. (A few other fluids that are acceptable have flash points around 60C.)

Thank you for the information, and for the life of me I couldn't find it for some reason. Based on your chart there, I was able to correctly form a search to find this: http://www.sintelub.com/files/Therminol_VLT.pdf

For this, the heat capacity starts at -180C @ 1.36kJ/kg*K
For a target temperature of -40C @ 1.7kJ/kg*K
And the warmer it gets, the better heat capacity it gets.

Mineral oil has a heat capacity of 1.67kJ/kg*K, so it's pretty much the equivalent, and while water has a value of 4.19, I checked out Novec fluids and they're in the 1.1-1.3 range. So heat capacity wise, this seems to be superior, correct?

Also a quick note about viscosity, in comparison, Therminol is at 1.83mPa*s, while water is at or less than 1. (This should also prove to be better than mineral oil at any temperature.)

And then considering flammability, from what I understand the Therminol fluid has (This is the big part my further research and EDIT addresses):

- Auto-ignition temperature is 264C
- Maximum bulk temperature starts at 175C

Now, while this might be flammable, what are the chances of that happening? I know at the very least temperatures won't reach that point, so what other concerns would I have in comparison to mineral oil? (EDIT: I've later come to understand the difference, as well as research the specific tests used for auto-ignition and flash points, etc.)

SDS Precautions are the standard it seems though the one of P210 of keeping away of hot surfaces might be concerning. But this precaution applies to anything that isn't in a flammability category of 0.

This gets kind of confusing, and would take a little more sorting out on my end, since it seems that the scales switch back and forth where 0 is horrible at times, and others 4 is the worst case for category rating. If you have further insight into this, concerns, or flammability in general especially compared to mineral oil that reaches 90C, please let me know.

One thing of note was that it specifically mentions flowing liquids as a source of static electricity, so I'd have to take into account grounding the system properly.

References:
Novec Fluids
Engineering Tool Box
Therminol VLT SDS

EDIT: I'm going to put together a chart, but needless to say, I do appreciate your concern and while I would eventually get to those points, it's good to have the backup and quick direction pointing.


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## billbartuska

When dealing with flammable liquids one should know the volatility (evaporation rate) and the LEL and UEL (Lower and Upper Explosive Limits).

On dealing with flammability:
The object of the game is to eliminate all possibility of ignition/explosion. This is done by considering all possible scenarios that could lead to those conditions.
The mere fact that "all" possible scenarios have to be considered makes this a daunting task. The probability of success depends greatly on the skill of the designer.
The easiest, cheapest, most likely to succeed method is to eliminate the flammable material. That eliminates all the possibilities!


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## Tellik

This I agree with, removing the flammability aspect to a safely manageable level. It's partly why I did a lot more digging into it, and have put together a table. I've been editing the previous post, but I'll also post it here as well.

https://docs.google.com/spreadsheets/d/142ms5DROTb_amCmHY8VBQ2kdY_Zz9u4nyFobxLPNY0A/edit?usp=sharing

Going to take a little more research into it, but a flash point of -7C is completely unacceptable. Ideally I would like to aim for 130+, as there should be no point I should ever get close to that limit, but then I have the other considerations to take into effect as well.

Right now I'm looking more into the LT and ADX-10 fluids, but I'll keep looking. I would like to think that Therminol has a solution in there, but it'll take some research to verify it. LT would be doable, but I would have to implement some restrictive safety measures in there and probably wouldn't be able to make it work safely. D-12 is looking more reasonable, and while it doesn't have too much better of a flash point, it's a little bit more improved. But either way, there are a lot more variations of Therminol fluids.


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## billbartuska

Fluorinert

Properties

MSDS

Price: Expensive


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## Tellik

Yeah, that is the downside to those fluids, where they are kind of costly. It's the reason why I'm avoiding them and Novec.


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## [ShowMe!]

You are looking for this.

Low Temperature Dielectric Silicone Fluids

http://www.clearcoproducts.com/dielectric-silicone-fluids-low.html

These designer chemicals are great an all, but you are no bill gates.

So to satisfy your over clocking cravings, get a chest freezer from walmart.com for 125$ with free shipping. Seal the seams on the inside with, silicone sealant. FIll it with about 35 to 50 gallons of distilled water. Drop a temperature controller in their set to positive 5 degrees Celsius. Drop a couple of submersible pond pumps in their. Drill a couple hole in the top lid. Build a chill box right on top of the chest freezer and put your whole computer inside. Dial in overlook and enjoy.

Cheap
No toxic chemicals
Energy efficient
Low noise
Monstrous reservoir of cold liquid
No dust on your parts
Cool the whole rig
Including hard drives and psu
5c water will get you a good overlook
it's a proven concept

You just have to live with a chest freezer in your room...
http://www.xtremesystems.org/forums/showthread.php?262843-The-Freezer


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## [ShowMe!]

Also http://www.overclock.net/t/1533164/the-24-7-sub-zero-liquid-chillbox-club/0_100this


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## Tellik

Quote:


> Originally Posted by *[ShowMe!]*
> 
> Also http://www.overclock.net/t/1533164/the-24-7-sub-zero-liquid-chillbox-club/0_100this


I'm definitely going to have to check out some more about the chill box concept. I should be able to use some ideas there, and from what I've seen already, there are some detailed things that would be useful. (Such as specific components you guys have used, etc.)

After doing more looking, and at the fluids you've mentioned as well since they gave me more ideas of things to look for, I've come across something that shows some promise.

Dynalene fluids, specifically the FC-BG fluid. http://www.dynalene.com/v/vspfiles/templates/210/datasheets/Dynalene_FC_Technical_Data_Sheet.pdf


Thermal Conductivity of .325378 W/m*K (Water is 0.6)
Specific Heat of 3.546 kJ/k*K (Water is 4.187)
Viscosity of 0.6815 Pa*S (Water is 0.653 @ 40C)
Pour Point of -40C (Usable range would be more around -30C+)
Conductivity of <10 uS/Cm (DI Water is 0.1)
No flash point or autoignition temperature, non-toxic, non-flammable, corrosion inhibitor


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## [ShowMe!]

In my opinion it's not worth. It's most likely going to be hard to pump at that temperature, cool less, and you have to deal with all the downsides of immersion.

You can run a normal liquid cooled system at -30 all day long inside a chill box. With forced chilled air cooling inside the chill box will give you 99% of the benifits with out the problems of immersion cooling.

I understand that immersion cooking sounds really cool, but after messing around with a minimal oil pc, I realized is a huge hastle.

I also think you might actually get a worse performance on the die area, when comparing a block at -30 and immersion fluid at -30.

I have not really found any systems running in below zero conditions in an immersion setup.

By far the most practical, cheapest, and the most successful in terms of over clock and 24/7 stability is the chiller + chill box concept.

It's easy to maintain and work on or modify or swap components.

That being said, if your rich, and got that $$$, please do continue with this project because I am curious to actually see the performance of an immersion system under load at -30c.

You would be the first, that I know off.


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## ssateneth

delete


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## Tellik

Quote:


> Quote:
> 
> 
> 
> Originally Posted by *[ShowMe!]*
> 
> http://www.clearcoproducts.com/dielectric-silicone-fluids-low.html
> 
> 
> 
> I must say, they have some pretty good fluids here that have decent flash points along with thermal properties. There's a lot though, kind of like the other synthetic oils, so I'd have to look into it more.
> Quote:
> 
> 
> 
> Originally Posted by *[ShowMe!]*
> 
> In my opinion it's not worth. It's most likely going to be hard to pump at that temperature, cool less, and you have to deal with all the downsides of immersion.
> 
> Click to expand...
Click to expand...

For this I would agree. I would like to avoid oil based products, which I do believe I've found.
Quote:


> Originally Posted by *[ShowMe!]*
> 
> You can run a normal liquid cooled system at -30 all day long inside a chill box. With forced chilled air cooling inside the chill box will give you 99% of the benifits with out the problems of immersion cooling.


I've been looking into the whole chill box concept, and while it does work, it isn't exactly what I'm aiming for. I might try this sometime, but that'll be a future project I'll probably do for a server that I can stick in an out of the way place. There are a lot of concepts I've been able to take from the chill box design that should help the immersion project.
Quote:


> Originally Posted by *[ShowMe!]*
> 
> I understand that immersion cooking sounds really cool, but after messing around with a minimal oil pc, I realized is a huge hastle.


I've definitely kept an eye on the downsides of immersion in general, much less using oil based. If I stay away from oil based liquids, I should be able to mitigate a lot of these issues.
Quote:


> Originally Posted by *[ShowMe!]*
> 
> I also think you might actually get a worse performance on the die area, when comparing a block at -30 and immersion fluid at -30.


This is something I'm going to have to consider. The general idea would be to maximize surface area and heat transfer. Which means I'd have to take into account of the fluid's reaction to thermal paste, etc. If I maximize the surface area of the heat output, then I can maximize cooling to that area.
Quote:


> Originally Posted by *[ShowMe!]*
> 
> I have not really found any systems running in below zero conditions in an immersion setup. By far the most practical, cheapest, and the most successful in terms of over clock and 24/7 stability is the chiller + chill box concept. It's easy to maintain and work on or modify or swap components. That being said, if your rich, and got that $$$, please do continue with this project because I am curious to actually see the performance of an immersion system under load at -30c. You would be the first, that I know off.


From what I've estimated so far, the most expensive portions of this would be if I actually put a new computer in there, instead of using an older one. That, and if I decided to go with custom made enclosures, etc. I've already started pricing out various components and it isn't looking too bad. One insulator I've taken an interest in is Aerogel.
Quote:


> It's most likely going to be hard to pump at that temperature, cool less, and you have to deal with all the downsides of immersion.


Dynalene FC-BG fluid, with a viscosity of 0.6815 Pa*S (Water is 0.653 @ 40C), should combat the pump ability of the fluid, and the thermal heat properties are almost comparable to that of water, and better than any mineral or oil based coolant out there. The one downside to immersion I'm aware of is that when you want to remove a component, you have to deal with the fluid coating it. With the FC-BG fluid, from what I understand it should evaporate on it's own. Especially at higher temperatures when it starts generating vapor.

Now with this fluid specifically, a lot of these concepts aren't proven. However, Monday I'll be talking to a company rep to discuss a ton of specific questions I have about this fluid and try to get a feel for how it would work.

Project is still going, my next major event will be on Monday when Dynalene has one of their engineers give me a call.


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## Tellik

Quote:


> Originally Posted by *ssateneth*
> 
> delete


Ah, I hate seeing this sort of stuff because I'm curious as to what you originally said. If you still feel like saying it, feel free to PM me.


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## ssateneth

Quote:


> Originally Posted by *Tellik*
> 
> Ah, I hate seeing this sort of stuff because I'm curious as to what you originally said. If you still feel like saying it, feel free to PM me.


It was just me complaining about how using an off-the-shelf chest freezer to contain and cool a PC wasn't feasible due to how it dumps its heat, and explained my experience when I tried it. Then someone linked using a chest freezer to maintain -30C temperatures or something under load. So never mind.


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## Tellik

Quote:


> Originally Posted by *ssateneth*
> 
> It was just me complaining about how using an off-the-shelf chest freezer to contain and cool a PC wasn't feasible due to how it dumps its heat, and explained my experience when I tried it. Then someone linked using a chest freezer to maintain -30C temperatures or something under load. So never mind.


I wouldn't really say that they're using a chest freezer to cool a PC. While I did look at that, the temperatures that a chest freezer can get to, and the heat capacity for removal are very low to the point where it just isn't feasible. Most of these chill boxes use a system where there is a container using an AC radiator to cool the liquid, a reservoir to store a large capacity of chilled liquid, and then the chill box itself that contains the PC. These chill boxes utilize thermal management with a radiator inside, as a sort of condensation/heat sink allowing safe water cooling at subzero temperatures. At least that's in a nutshell what I gather from the whole chill box concept.

What I'm attempting to do is kind of a little bit similar in nature, especially compared to what Orthello's design is like.

Now a large part of this will depend on what my conversation with Dynalene entails, but the general concept is:

Cooling Source -> Submerged PC, and that repeats on a loop. The cooling source will be maintained outside or in an enclosed remote area, and there will be no moving parts inside of the PC. Of course there's a far more complex version, but I'm still working on the details and how I can overly complicate the system to ideally maintain target temperatures under any load.


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## Tellik

After talking to the Dynalene representative and discussing the future goals and qualities of the fluid, it turns out that even though the fluid has a good dielectric strength, the breakdown voltage isn't so good. Basically, it's perfect for closed loop water cooling systems when you want the peace of mind that leaks aren't going to cause any sort of problems, but past incidental contact, it won't work.

However, as a company they're working very well with me to get me exactly what I need or what would work best. They have their own R&D department that the guy I talked to said he'd ask them, though if I needed to get a fluid designed from scratch that wouldn't be free. Also I should be getting some 1 gal samples of some of their other fluids that should work better, for material compatibility, temperature, etc, that I can test out here. The next guy I need to talk to that deals with these specific fluids that they'll be hopefully sending me is on vacation right now, so I'm going to have to push that back a little bit while I work on other design aspects.


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