Keeping a cool head


We are constantly talking about the need to keep our office environments cool and the effects that overheating could have on the occupants within those environments. It is very rare however that we discuss the need to keep our computer systems cool. But when those systems are mission critical it becomes essential and we have to ensure that they remain working at all costs.

The IT backbone

Mission critical facilities provide the IT backbone in many organisations but especially those in the banking and finance sectors where the trading desks are the lifeblood of the organisation. Imagine for a second what would happen if these systems failed and the potential loss of money which would result from that? Probably not something you even want to consider if you work in this sector, but the point of this piece is that your worries could all be in the past thanks to a new development by Trox AITCS, in collaboration with its partner, Star Refrigeration, who have developed an innovative cooling solution by harnessing carbon dioxide specifically for blade server cooling.

I spoke to Guy Hutchins Sales & Marketing Director for Trox AITCS to find out more about this new technology which is being billed as the low risk solution.

Conventional cooling

Conventional cooling systems employing air and water are now considered outdated and unable to deal with the rapid advancement technology has placed upon them. With an increased need for data processing, blade server heat loads are far higher than those experienced in the past and the new CO2 solution is ideal.

The basic principal and design philosophy of the Trox patented CO2RAC product is to absorb all the heat rejected by the blade servers, making the blade neutral to the space. By using pressurised carbon dioxide in its liquid form as a cooling medium and circulated at 14°C, Trox has utilised a natural substance that is significantly less potent than HFC greenhouse gasses.

IT professionals will quickly appreciate the benefits the revolutionary C02RAC cooling system will bring as increased efficiency is created by the cabinet’s capacity to handle higher loads. Conventionally air cooled systems can only deal with between a 5kW and 8kW load while cabinets cooled by C02 can manage up to 30kW. This results in fewer cabinets for the same total load. Typically, you can get up to six blade server chassis into a 42U cabinet each with a load of over 3kW. The CO2RAC system can easily cope with this requirement and even allows for future increases in the server loads.

The technology

The relentless advance in high capacity computer equipment is typified by blade servers housed in cabinets, which produce very high heat loads meaning that the cooling system must cater for loads of up to 30kW per cabinet. Conventional cooling solutions using air or water are unable to deal satisfactorily with these sorts of loads.

The heat loads generated by modern technology often demand more than one thousand air changes an hour, a rate that is impractical to provide. To achieve an even air distribution across the floor and then through the technical space is all but impossible.

Water is a more efficient cooling medium than air, but it is also a conductor of electricity, and can damage ICT equipment if the two come into contact.

Carbon dioxide, on the other hand, is a perfect cooling medium for ICT because it is:

• Electrically benign, and non-hazardous to servers and cabling.

• Able to offer cooling seven times better than water, which allows reduced volume flows and smaller diameter distribution pipe work. Also, heat is absorbed during a ‘phase-change’ process with no rise in temperature.

• Of lower viscosity and volume flows than water, cutting pumping power consumption, and resulting in energy savings of up to 30 percent.

Also carbon dioxide is a low cost as its ample supply is derived as a waste by-product from industrial processes and therefore in this application can be considered as having a negative Global Warming Potential.

All these advantages led Trox to develop a carbon dioxide-based cooling system for ICT called CO2OLrac.

CO2OLrac is designed to absorb heat at the rear of the cabinet as it is rejected by the servers. Even when the cabinet door is open around 60/70 percent of the server heat is absorbed by the CO2OLrac unit. With an open door around 30 to 40 percent of the equipment heat will spill out into the aisle, thus raising the local ambient temperature by around 1 to 2°C. This will be absorbed by adjacent cabinets.

The system design is based on circulating CO2 at a temperature of 14°C, above dew point thus avoiding condensation. The liquid CO2 absorbs the heat across the coil, and ‘boils off’ to a vapour which is held in suspension. The greater the load, the greater will be the concentration of vapour within the CO2.

The CO2RAC unit is fitted with five fans, which create a negative pressure within the rear of the cabinet. The unit also incorporates a digital temperature display to provide a visual indication of the off-coil temperature in each cabinet.

An LED indicator fitted to the CO2OLracs provides a rapid means of locating those that require maintenance. Failure indication will also raise the alarm at the building management system.

The market

This new system is definitely a step in the right direction for the IT professionals, but at the same time it looks like it could be a solution to many more problems.

There is an obvious benefit to the new-build and retro-fit markets but at the same time there is a benefit to the specification market as this type of system provides a massive selling point if the property is destined to be let to a bank or financial institution. Guy says: “The opportunities for both retro-fit and new-build are numerous but at the same time the property developers are also starting to show an interest. If they have already identified a property for a certain type of client with specific technology needs, it would be a smart move for him to introduce a high capacity CO2 system as a unique selling point and to improve the chances of letting the building.”

The cost factor

As with any new product on the market there is the small matter of cost and the obvious fact that if it is new technology then there is bound to be a cost premium which comes with it – so is it worth the extra money? Guy says: “There is undoubtedly a price premium with this system but what price do you put on a low risk cooling solution. The alternative could be that the servers overheat and the computer system crashes, something which could have devastating effects if it is a bank’s main trading system.

“We are not just selling a new product which will help the efficiency and day to day running of the computer system; we are selling peace of mind in the form of a low risk solution. You can compare this system with other types of cooling systems but it stills come back to the fact that you cannot put a price on a low risk solution so if someone says that they can’t afford this system I think that the question which needs to be asked is can you afford not to?”

And finally

It’s not often that a new system comes along that genuinely is a good idea but with this I think that we have found one. It really does make sense to pay the extra pound because with such a low risk and efficient system it doesn’t make any sense at all to take unnecessary risks.

Although this has only just been introduced to the market (official launch 1 Feb) I can certainly see a time when most of the buildings with mission critical systems will house this type of technology to protect their servers and while we all begin to adopt this technology we can only look forward to the new developments which will certainly follow.

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