Submerged system optimization


Dec 29, 2012
Hi all,

Let me start of by saying: Yeah another one. Another one interested in oil submerging a system. However I am particularly interested in looking beyond the aesthetics. Let me explain.

From the very start of computers we've been working with aircooled components. First we started with components directly giving their heat of to the air. After that we added sinks, fans, tubing, the lot. Then came watercooling, and now... well we're optimizing what we have. Radiators are added, more tubing, coolants, and let's be honest we've come quite a long way.
But ever since I first heard the smallest rumour about liquid submersion I've been intrigued. It's a hassle, a mess and whatnot, but it sounds like fairly new terrain, only recently confirmed by Intel that has said to be testing the idea.

So let's look past the obstacles and look for solutions. That's why I came here. I've been reading up about the idea for quite some time, and especially here there seems to be quite some knowledge. I'm looking to do something new, after several standard builts I want to see if it's possible to create something new that actually works better than what is out there. Let's not forget there was a time that watercooling sounded stupid too, and look at how many are now working with it.

On to what I have:
- Mobo orientation: I prefer to have the board mounted horizontally. Heat wants to go up, why fight this by placing your mobo horizontal. Apart from space issues there are no real objections to this. The argument that heat builts up in the top of your case is not relevant, because this is not a standard case I want to built.

- "Your case will leak". This seems to be one of the most common arguments I've been hearing. I feel this is not an issue as I want to built a case that functional, not specifically the best looking thing out there. That means automatically that I will step away from stuff like acrylic cases and such. They have zero functionality, other than looking nice that is. By making an aluminium bucket without any holes for ports or wiring, this problem should be solved. Aluminium doesn't dissolve in oil.

- You can't easily replace parts anymore. I think this is not relevant. Most only swap parts every so often, and it's not that big of a hassle. You are still able to swap stuff, it's just a little more slippery than it would be otherwise. Watercooling wasn't really easy in the beginning either.

- Oil eats away at your components. I'm still not sure on that. I've read multiple builts that have no problem at all with components falling apart, while at the same time I've read some minor problems with capacitors that swell and such. I have a feeling that it won't be such a problem.

- The biggest reason to step away from oil seems to be that it offers no real benefits, though it has been confirmed that it offers some great properties in a computer. It helps reduce hotspots in your computer, it's quiter than air cooling, helps to keep dust out of your computer, and you can increase the load on components more because it takes longer for the oil temprature to rise. As the oil replaces air, this is an advantage. It keeps your components cooler for a longer period of time.

This bring me to the main part of this topic: it seems to be hard to get the oil to lose the heat again. Because oil is "slow" it takes a while to heat up, but at the same time it takes time to lose the heat again too. The fact that all other builts I found were made of glass or acrylic is just bad design I think. Those materials are not made to transfer heat. They basically make sure the heat in the oil has nowhere to go, and causes your system to heat up. It takes a while, but it'll get hot. By using your case as the primary heatsink, and making sure you have good flow in your case you should be able to combine the advantages of the oil submersion with the advantages of other cooling methods. Basically removing the heat from the places where you don't want it, by spreading it over the oil, and then in turn spread spread that heat over the surrounding aluminium case. Simplified: Making an enormous heatsink for all your components, using the oil only as transport for the heat, instead of the actual coolant as most seem to be doing.

I've been busy drawing what I think would be a good design that would actually work. I'm missing details, also fans, but I think the idea is clear enough.

I'll explain it from the bottom up:

- Bottom part contains drives, but also the PSU. There is no need to also submerge that part. It get's warm, but it's not something that you easily overheat. You don't overclock them, so why warm up your oil with useless stuff. PSU sits at the bottom. It has feet that can be screwed in or out to place it stable and level.

- Middle: This is basically the outside part that counts. The aluminium bath is place inside this part. It helps direct airflow to the fins, but also creates a gap for the fans to suck air from that is then blown through the fins. I've designed it for four 200 mm fans. The space is there, and because of the size they can be set to slow speeds.

- This brings us to the core. This is an all aluminium core, with fins to create a larger surface for the air to pass by. But there are also fins on the inside to create a large surface area for the oil to pass by.

- There is an acrylic hood inside. This helps with flow. As the centre of the aluminium bath creates the heat, this rises to the top of the hood. Like a volcano this goes to the top. A fan should be placed here to help draw the heat up. As the warm oil gets pulled up it's then expelled at the top. At the same time cooler oil is drawn in from the bottom. For the warm oil to reach the bottom again, it needs to pass the outside edges of the aluminium where it is cooled. This is a constant circulation. With the addition of smaller fans, flow of cool oil can be directed towards specific components like CPU and GPU.

- Ofcourse there will have to be a cover. This can be acrylic, it's mainly a window to look inside and see if everything is ok. Making this an aluminium cover would have almost no thermal benefits.



So, a lot of text. I'm curious to see what you guys think. I hope it makes for an interesting discussion, and your inputs are more than welcome.

Have a good night.