Anandtech [Anandtech] Raijintek Pump-less Phase-Change Closed-loop Liquid Cooler

http://www.anandtech.com/show/10398/raijintek-shows-off-pumpless-liquid-cooling-system

Interesting concept...but the radiator must be installed above the block (I'm wondering if there are any additional orientation restrictions) and the operating environment must be suitably cool (they gave Qatar as an example where this would not work because it can get above the 40°C boiling point of the phase-change coolant).

 

[Phuncz]

Placement can often be an issue with a CPU cooler in an SFF case, you need to research if it can fit. For your Bolt build as an example it's not suited because of the way the radiator is mounted. It won't even work in the Ncase M1 or Kimera Cerberus because of the same reason. But it's not crazy to see future cases taking this product into consideration when it becomes a thing. Right now it's too early to tell, it might just as well fizzle like the other revolutionary cooling products we have seen and have never seen again.

 

[|||]

The Bolt II can be laid over on it's side (it has 1/2" feet specifically to do so), so that cooler could conceivably be used. I'd still be concerned with the routing of the tubes through the case, as they can crimp a little with some of the tight bends.

The Bolt III uses the Lian-Li PC-O5S case, which might be an excellent candidate for this with a 240mm radiator space on the top side. Granted, it is fairly large for a SFF system...

But the point is that it could be possible to use a phase changing fluid in a closed-loop system other than a heat pipe or vapor chamber.

 

[EdZ]

I'm actually VERY interested in how this works out as a product, particularly loop sealing and pressure-relief requirements. Though not as a product to purchase as such.

On the back-burner for a while now has been a design for a ruggedised 'deck' for portable VR use, one of the key features of which would have been the entire core operating parts of the system (CPU, GPU, mobo, PSU) being folded together and sealed in a tank of Fluorinert or Novec, (or another perflurocarbon mix). A 'flip-up' radiator would provide whole-system cooling as well as act as a mount for the optical tracking system. Integrated into the shell would be a waterproof keyboard (with cover that flips up with a monitor in the keyboard lid, if I can track down the hardware to drive one of the ultrawide laptop panels from a U845W or Vaio P series directly). As long as the heat sinking capacity of the radiator were not exceeded, all components would be held down to the phase-change temperature of the cooling fluid, with the entire system being effectively waterproof and dustproof.
The main holdups are:
- Determining the quantity of fluid needed (as little as possible from a cost and weight standpoint, but too little means the system can 'run dry' in warm environments, tilted environments, or just if the radiator cooling is insufficient)
- Determining what CoTS radiators, if any, could cool a vapourised perflurocarbon effectively. This is the interesting part of the Raijintec solution, it looks like just a regular WC radiator may be sufficient, though they did not demonstrate it with a CPU.
- Cable egress sealing for the main tank.
- Determine lifetime effectiveness of perflurocarbons in operation. Fluid loss from leaks, attacks on substances in the loop (should be EXTREMELY benign in theory), moisture ingress, gas flow paths inside the sealed chamber, rotating plumbing for the flip-up radiator to avoid gas traps, etc).
Experimenting on these means having plenty of coolant to hand, and that stuff is prohibitively expensive for a project that will never be able to pay for itself. £300/L is the sort of typical pricing, and it evaporates at an ASTONISHING rate. Nearly twice the density of water, but vanishes faster than pure alcohol if left unsealed!