An associate professor of mechanical engineering at the University of Wisconsin-Madison has developed a liquid cooling system he says is safer than water cooling and could cut cooling costs of data centers by up to 90 percent.
Data centers are growing at a rate of seven to 10 percent per year in the U.S., and associated cooling costs are on the rise as well, says associate professor Timothy Shedd, who has spent more than a decade studying and designing computer cooling systems. Currently, cooling costs at server farms owned by companies such as Amazon and Google are about $2 billion per year, or 10 percent of the capital cost. Cooling system selection is also limited, as only three companies make and install most of the big systems needed.
Shedd’s new liquid cooling system is comprised of a plastic chamber attached to the processor that absorbs heat and pumps it away via fluid inside a network of tubes to the roof of the building, where it is dispersed into the atmosphere. The system is unique in that is does not include a compressor, condenser or evaporator, which are major parts of air conditioning systems used to cool many data centers today.
In addition, says Shedd, the refrigerant inside the new cooling system would not cause damage to the computer if it were to spill, a concern that often makes data center operators nervous about installing water-based liquid cooling systems. However, because the refrigerant carries less heat than water, he must ensure that the fluid boils in the chamber atop the chip and condenses back to liquid on the rooftop heat disperser. This “phase change” ramps up the heat transfer rate without threatening the processor.
Shedd’s cooling system has been in use for five months nonstop thus far by a group of servers at the UW-Madison College of Engineering. A spinoff business called Ebullient has also been started to commercialize the new cooling system.
