After two years of testing, the University of Leeds is now installing the first production systems of a liquid-cooled computer server. UK company Iceotope designed and built the new server working with team of researchers from the University.
Rather than using air to cool the electronics, the components in the Iceotope servers are completely immersed in liquid. The non-flammable liquid coolant, called 3M Novec, can be in direct contact with electronics because it does not conduct electricity.
Other coolants are used in the cabinet to transfer the heat, which ends up on an external loop, taking it away for cooling or reuse. This external loop can use ‘grey water’ sources such as rainwater or river water, further reducing the environmental impact of the server. And the efficiency of the system means that the output water can reach temperatures of up to 50oC, which can be used for heating and other uses.
Using liquid to take the heat away, rather than relying on fans, makes the machines much quieter, but more importantly saves power. Its designers estimate that the server cuts energy consumption for cooling by between 80% and 97%.
Dr Jon Summers, who leads the University team, said: “The liquid we are using is extraordinary stuff. You could throw your mobile phone in a tub of it and the phone would work perfectly. But the important thing for the future of computing and the internet is that it is more than 1,000 times more effective at carrying heat than air”.
The Iceotope system uses just 80 watts of power to harvest the heat from up to 20 kilowatts of ICT use. The server also does away with the need for ancillary data centre facilities such as computer room air conditioning (CRAC) units, humidity control systems and air purification.
Review: It does seem intuitive that if you could cool electronic components with liquid it would be much more efficient. But experience also suggests that electricity and liquid don’t mix. Now it seems that with the right liquid they do.
There’s going to be a mountain of scepticism to overcome, though, about containing the various coolants, the stability of the liquid, etc. Liquid cooling has a long history in the IT industry, but not with the liquid touching the electronics (except by mistake!), so data centre managers are going to need some convincing that it works and that it’s safe and dependable.
But at least the technology is out there and is another cooling possibility, particularly for new data centres. If you have to use cooling equipment then this seems a very environmentally- efficient solution. Deciding the best way to remove heat from a data centre is becoming an increasingly complex decision, but the good thing is that there are now various alternatives to power-hungry and wasteful air conditioners.