The world’s data centres, sometimes criticised for energy waste, use about 31 gigawatts of power, according to a 2011 report by Datacenter Dynamics. That’s equal to around half of total peak electricity demand in the UK.

Another report (by McKinsey and Company in 2008) projected that data-centre carbon emissions will quadruple by 2020. And the UK already has around 7.6 million square metres of data-centre floor space.

Cutting the Internet’s carbon footprint is thus a priority. And it looks as if researchers at a British university may have found a solution. They’re currently testing a potentially revolutionary liquid-cooled computer server design.

Most computers use air for cooling, but all parts of the new server being tested at the University of Leeds are immersed in liquid. Instead of the usual power-hungry fans, a liquid-cooling process that is silent and depends on the natural convection of heat is used.

 Working with researchers led by Dr Jon Summers of the University of Leeds’ School of Mechanical Engineering, the UK company Iceotope designed and built the new server. Prototypes have been tested over the last two years, and now the first production system has been installed at the university.

Cuts energy usage by up to 97%

The server cuts energy usage for cooling by an estimated 80% to 97%. Dr Summers says the liquid used is more than a thousand times more effective at carrying heat than air.

The liquid coolant, called 3M Novec, does not conduct electricity, so it can be in direct contact with electronic parts.

So how does the coolant flow over the components? At the bottom of the cabinet, there’s a pump, which uses little energy, that pumps a secondary coolant up to the top, and then, thanks to gravity, this coolant flows down through all 48 modules.

The secondary coolant stops at heat exchangers in the cabinet so that heat is transferred to a third coolant, on an external loop, and in this way the heat is removed away for cooling or even reuse.

Adding to the solution’s environmental friendliness is the fact that the third coolant can be derived from sources such as river or rain water, while the output water can get as hot as 50 degrees Centigrade, so can be used for heating and other purposes.

The system uses 80 watts of power to gather the heat from up to 20 kilowatts of ICT use.

One of the other beauties of the system is that ancillary data-centre facilities – such as air purification, computer room air-conditioning (CRAC) units and humidity control systems – are not required.

Because the system is completely enclosed, says Dr Nikil Kapur, a member of the research team, it doesn’t interact with the environment like an air-cooled server. That means it could work in an extreme environment such as a desert. And, of course, the fact that it is silent means it can be placed in any room and won’t disturb anyone with an irritating background noise.

Iceotope’s Chief Technology Officer Peter Hopton is quoted on the University of Leeds website as saying: “More than five years of research, innovation and collaboration have gone into Iceotope’s technology. The basic principle of the design has many applications and, while a few years away, there is no reason why every home shouldn’t make better use of the surplus heat from consumer electronics.

“Imagine having your PC or TV plumbed into the central heating system.”