UCal prototypes negative pressure liquid cooling system
updated 12:40 am EDT, Wed September 26, 2012
New system prevents leaks, increases energy efficiency
The California Institute for Telecommunications and Information Technology (CALIT2) at the University of California San Diego has launched the test for a new server farm cooling technology. A negative-pressure liquid cooling system has been deployed on a three 1U servers in the Calit2 server room to test both the efficacy of the setup as well as the energy efficiency improved by the use of the liquid cooling system.
The technology is a rack-based, direct-to-the-chip, leak-free liquid cooling system that can be tailored to cool any server. The developer, Flometrics, Inc, installed it's Chilldyne Cool-Flo pump derived from rocket engine-cooling technology developed with a grant from NASA's small business innovation research program. The system runs in parallel at negative pressure and is driven by both a pump and natural circulation. The negative pressure installation operates at lower than atmospheric pressure minimizing the effect of any leak. Cool-Flo also implements a no-drip hot swap connector which allows technicians to remove servers without shutting down the entire system for maintenance.
"Not only is there an advantage of power reduction by 25 to 35 percent, but you are lowering existing CPU temperatures by 30 degrees Celsius, resulting in practically unlimited density," explained CEO of Flometrics, Steve Harrington. "Cool-Flo is a good fit for Calit2’s server needs given the institute’s commitment to reducing the energy intensity of campus IT and improving energy efficiency." The systems power need reduction over conventional cooling solutions are derived from the reduction of air conditioning requirements, a reduction of CPU energy losses to heat, and reduced power required to run the servers' fans.
The system differs from commercial PC liquid cooling systems found in enthusiast systems and some of the Apple G5 line in the pressure of the system. The Calit2 system operates at pressures below atmospheric pressure, so in the event of a leak, the higher pressure outside prevents leakage. Normal PC cooling systems operate at a positive pressure, so any leak of fluid escapes the system into the environment or into the computer itself.
