Green Revolution Cooling has released a liquid cooling system that takes a novel approach to liquid cooling: submerging!  While the very thought of submerging a $10,000 compute blade into anything liquid makes our hair stand on end, Green River’s approach appears to easily work.
Here’s how it works, in a nutshell.  From GRC’s own web site:
Since GR Cooling technology requires such a radical change in thinking, a simple process overview is provided for the three components: the rack, the cooling system, and the control system.
After 60 seconds of modification the server is set into the rack and submerged entirely in GreenDEFâ„¢ coolant. The coolant, a far superior cooling medium compared to air, effectively captures 100% of the server heat. With the trapped heat, the coolant then flows outside without heating the air in the server room.
The rack reorients servers and fully submerges them in a non-conductive coolant which captures 1,300x times more heat by volume than air. The superior heat dissipation qualities of the coolant provides more uniform cooling for even the highest density servers.
The cooling system moves the heated GreenDEFâ„¢ coolant to the outside heat exchanger where heat is rejected and the coolant is returned.
The control system carefully controls coolant mineral oil flow and heat exchanger fan speed to ensure the cooling process is always efficient.  Advanced features such as redundant temperature, pressure and coolant level instrumentation, smart monitoring, and intelligent optimization that alerts for failures or any other events allows for “lights out†management.
Overall GR Cooling provides a cost effective method to achieve the most efficient data centers in production.
You can read a quick PowerPoint Presentation from GRC that provides a simple, laymans explanation of their approach:Â Green Revolution Cooling: How it Works in Non-Technical Terms.