A group of scientists at the University of Alabama in Huntsville (UAH) developed a new closed-loop liquid cooling system that doesn't require a pump. The passive system uses a convection cycle, in the proof of concept the researcher let 3M Fluorinert FC-72 liquid make direct contact with a delidded processor and then utilize a heatsink as an external radiator to cool the liquid.
The 3M Fluorinert FC-72 has a boiling point of 56°C (133°F) so upon coming in contact with a hot surface it automatically starts circulating to the radiator where it condenses and becomes a liquid again. The fluid is colorless, odorless, biologically inert, no-nflammabe and an electrical insulator.
The convection cycle works as heat from the computer processor vaporizes 3M’s Fluorinert FC-72 and that moves the lighter fluid along to the heat exchanger where it condenses into a heavier liquid and makes the cooling loop again. The project was done by University of Alabama in Huntsville student Cuong Nguyen for his chemical engineering master’s thesis. Mr. Nhuyen was able to test the system on a system using Intel Core i3 processors with the integrated heat spreaders (IHS) removed and found that the system was able to work for a period of 12 hours without issue with a steady state temperature of 56-degree Celsius. This is the boiling point of Fluorinert FC-72.
The system eliminates noise, vibration and dust contamination. It's an interesting concept but we don't think it's ready for prime time. Downsides include the high cost of the fluid, limited cooling capacity and the fact that it can't cool below 56°C as that is the fluid's boiling point.