Some background

For those of you not familiar with the technology, the Trox CO2OLrac can cool heat loads of up to 30kW per cabinet making it ideal for cooling the latest high-tech blade servers found in a range of industries, including banking, finance, the military and healthcare.

The high capacity makes it far more efficient than the air and water-cooling alternatives, allowing the footprint of IT equipment rooms to be reduced by 50 to 70%, and thus saving valuable space in increasingly crowded computer rooms.

CO2OLrac additionally offers cost benefits. Because the system is packaged, installation time and expenditure are reduced dramatically. The integral R134a chiller/CO2 plant can provide energy savings of up to 30% and the compressor power consumption is reduced due to the elevated R134a temperature to provide CO2 at 14°C compared to CHW at 6°C. The system benefits further from reduced volume flows of CO2 versus CHW, along with its reduced viscosity.

A further benefit of CO2 is that it is electrically benign, ensuring it is safe for use in close proximity to computer servers and cabling.

Imperial College

The system installed at Imperial College is part of a refurbishment project in the College’s Mechanical Engineering Building and involved the installation of 15 Trox CO2OLrac units, each providing 20kW of cooling. Trox AITCS was responsible for the supply and installation of a combined air-cooled R134a chiller and carbon dioxide (CO2) plant, fully welded stainless steel secondary CO2 distribution pipe work and gas detection/isolation.

The CO2OLrac units were supplied with a mounting frame, giving Imperial College ICT staff the flexibility to rapidly install different types and sizes of equipment cabinets. A condensing unit backed by an uninterruptible power supply was also provided to protect the CO2 charge if a power failure occurs.

Trox AITCS installed the mounting frame, cabinet doors, and CO2OLrac units while the associated chiller plant and pipe work was installed by the company’s refrigeration partner, Star.

In practice

It’s all very well hearing what Trox have to say about a product but as with anything the real proof lies in the installation and the benefits which it gives to Imperial College. I spoke to Arthur Spirling, Deputy Director of ICT at Imperial College who says that this is indeed a unique solution which nobody thought would actually work.

“At Imperial College we have a unique need for high performance computing. We have a number of researchers in medicine, engineering, physical sciences and natural sciences, who all need to run hugely complex algorithms. In order to do this they need high performance computing which tends to be made up of a number of racks of components. When you have hundreds of these components all racked up in one unit the heat output is 20kW plus which is what makes it so unique.

“When we originally started talking to architects about our requirements I was told that I didn’t need 20kW of cooling per cabinet, because few people in the industry could understand fully the need that we had.

“We were given a number of alternatives such as only half filling the cabinets or putting fewer cabinets into the space available but this basically meant that we couldn’t achieve the best solution for Imperial College. We are a prime site in West London and we can’t afford to dot the units around because we only have a finite amount of space to site the units. We needed to be able to get the maximum number of cabinets into the space which we had and therefore we needed the concentrated cooling which Trox AITCS could provide.”

With space in many cities becoming a premium this is a problem which more and more companies have to face, and as pressure on the computer system continues to grow the only option which will ultimately make sense is a concentrated cooling solution. But will that come at a price premium and are Imperial College having to pay highly for the solution which they have?

Senior Project Manager Kieran McDaid says not: “As with any project we had a budget which we had to meet and our ultimate aim was to get as many cabinets into the space which we had, it was up to us to find the right solution which achieved our aim for the right price.

“Having seen the Trox AITCS system we all agreed that this was what we needed, and in addition to the fact that it met all of our needs it was a cost effective option for us. It appears to be a less expensive to run than a conventional water cooled system and while it has only been up and running for just over nine months, and therefore we don’t have any proper data available yet, the figures which we have seen to date are very encouraging.

“We also liked the way that Trox AITCS operate in that they are a very innovative company who were willing to work with us to achieve our aims. When we first set out to specify this system we were told that we could only achieve 15-18kW of cooling per cabinet. Trox AITCS came on the scene and proved that 20kW of cooling was not only possible but that it could also be achieved within the timescale that we specified. At the beginning of this project no-one believed that this solution would work, but we stuck our necks out and I have been very impressed with the professionalism of Trox/Star in bringing this new and innovative product to market."

The way forward

Any system of this type is very exciting for the industry because it effectively changes the way in which we look at cabinet cooling. Space is at a premium and it is no great secret that the pressures being put on that space are increasing. A cabinet cooling system of this type basically means that we can re-write the rule book and that we can now achieve something which we only dreamed of five years ago.

We can now cram more cabinets into the available space and the great thing is that they won’t overheat and therefore there won’t be the many problems associated with small IT server rooms which we have seen in the past. This is surely goods news for those in the industry that have to maintain the servers and for those who pay ever increasing amounts to ‘put it right’ when the equipment overheats.

It may sound like a very simple and straightforward solution - and actually it is, because this type of cooling solution is something which many companies have been crying out for. The fact that we have now seen it in action at Imperial College just goes to prove that it can and does work and that it can provide a cost effective alternative to traditional cooling methods.

I think we can expect to see many more installations of this pioneering carbon dioxide based IT cabinet cooling system over the coming months and years because once it becomes common knowledge I don’t think it will be long before it becomes an industry favourite.

Printer friendly version

Email this article to a friend