CO2 used to cool blade servers

Cooling is becoming a hot potato for IT departments in terms of environmental issues and cost. But one UK company claims to have made a breakthrough in the use of carbon dioxide as a cooling agent which it claims could help combat the problem

The system, announced publicly on Wednesday, has been developed by Trox Advanced IT Cooling Systems (AIT), which hold the patents, in collaboration with refrigeration specialists Star Refrigeration. The first cooling units have been installed at Imperial College London.

Although at this stage the companies are releasing few details on exactly how its CO2 Mission Critical Cooling system works, a statement put out this week claims that the "principal philosophy is to employ heat absorption rather than conventional cooling — creating a more intrinsically resilient and energy-efficient solution".

The cooling system is mainly targeted at "high compaction cooling, particularly... blade servers where equipment loads may be in excess of 20kW per cabinet". The makers claim the device fits on the rear of a server cabinet and captures the heat that is being pushed out by fans. Acording to Trix AIT, "the heat absorption principle offers 'intrinsic resilience'".

The system enjoys "the high capacity, low energy and electrically benign benefits" offered by carbon dioxide, the makers claim.

Cooling systems down is becoming a major issue for data centres, particularly in cities where the need to cool down server banks, usually with electrical devices like fans, is coming up against limitations in the availability of power.

Mike Tobin of Redbus International, which claims to be the largest data centre operator in Europe, understands these problems well.

"For every kilowatt of power that is consumed we have to use three quarters of a kilowatt to cool it," he told ZDNet UK. "Anything that can help us in that area is welcome."

The problem of heat and heat dissipation has become intense, Tobin added — especially when related to blade servers. "Our average rack used to have four servers now it will have 80. The density is an issue in trying to deal with heat."

Tobin said he was looking at this latest carbon dioxide technology "with interest" but there could "some issues" that needed to be addressed.

"Is it safe? Carbon dioxide is dangerous if it leaks and builds up, so I would need to know that it is safe. And then there is perhaps a cost as well. All of the safety devices are there to monitor for fire and heat, will they have to be altered to monitor carbon dioxide build-up as well?"