Merits of Mineral Oil
Mineral oil has been used in immersion cooling because it is not hazardous and transfers heat almost as well as water, but doesn’t conduct an electric charge. Some mineral oil-style coolants can be messy to maintain. Patterson said Intel’s technicians always had an extra set of clothes handy to account for coolant spills. Green Revolution says its coolant can be drained for enclosure-level maintenance, and individual servers can be removed for work.
“I think it will catch on,” said Patterson. “It’s going to be a slow progression, but will start in high-performance computing and the need to look at performance upside. Those (HPC) procurements are large enough that this might make sense. Those guys are probably a little bit more sophisticated in their willingness to do something different.”
Green Revolution says its GreenDEF coolant can support heat loads of up to 100 kilowatts per 42U rack, far beyond current average heat loads of 4 to 8 watts a rack and high-density loads of 12 to 30 kilowatts per rack. The company says the system is designed to comply with fire codes and the Clean Water Act, and integrates with standard power distribution units (PDUs) and network switches.
Gains for Green Revolution
Patterson emphasized that Intel doesn’t recommend a particular vendor. “We are evaluating all types of oil immersion to understand the entire ecosystem,” said Patterson. Other players in the immersion cooling field include Iceotope and LiquidCool (formerly Hardcore Computer).
But there’s no question that the cooperation with Intel is an important validation for Green Revolution’s technology, which we’ve been tracking since the company’s launch in 2009. The technology is being used by an Austin colocation provider, as well as in HPC installations hwere it has demonstrated its ability to work with GPU acceleration and designs that recycle server waste heat.
This week Green Revolution announced that server maker Super Micro Computer is providing full warranty coverage for servers installed in the CarnotJet submersion system, which the company called a “momentous step forward” for its technology. The warranty will cover motherboards, backplanes, add-on cards, power supplies, and processors.
More broadly, submersion cooling may benefit from Intel’s affirmation that submersion doesn’t have any impact on hardware reliability. “When we pulled the servers out, we took them to our failure analysis lab,” Patterson said. “They could find nothing at all to suggest that this is a bad idea.”
In 2008, Intel published research showing that in many climates servers perform well when cooled with fresh air from outside the data center. At the time, this design approach – known as air-side economization or “free cooling” was used by a small percentage of data centers. With support from Intel and other large data center builders, fresh air cooling has since become a common feature in new data center construction in recent years.
Pages: 1 2