In an underground command centre, hidden below the streets of Westminster, experts gathered to debate the role of virtual reality in the war against wasted energy. Louise Frampton reports
At a recent panel discussion on the value of virtual reality in the data centre sector, held at London’s Churchill War Rooms, end users provided an insight into how they are using the software at every stage of the data centre life cycle to improve resilience, innovate and reduce costs.
As part of this discussion, experts shared their vision for adopting the use of simulation to reduce the threat of outages, caused by human factors, in the same way the aviation industry has used the technology to improve its safety record.
‘Virtual Facility’ (VF) is essentially a 3D mathematical model of a real facility, used as a test bed for experimentation. If you combine this with CFD software it is possible to safely evaluate the impact of any change to the data centre. Data centre operators can study the implications of different power, loading and cooling scenarios, to see how the data centre will cope. In short, the technology enables users to test performance, durability, safety and reliability in a risk-free environment.
One of the applications of virtual reality includes the ability to provide a communication tool, enabling designers to give clients a virtual tour of their proposals, with an immersive experience. Colocation providers can also use the technology to show customers a new cage layout and how it will operate, for example. When applied in operational sites, it is possible to overlay simulation and DCIM data to understand the data centre performance. It can also be used for site assessment, analysis and training to reduce human errors and failures.
So, do data centres need CFD more than any other buildings?
Julien de Charentenay, head of building physics, at Red Engineering, reports that 90% of the company’s work is on data centres. “You only have one chance to get it right,” he comments.
As the data centre industry moves towards reducing PUE and saving energy costs, attention has turned to the cooling plant. With up to 40% of the data centre’s energy consumed by the cooling infrastructure, there are significant savings to be realised with the latest technology advances in cooling systems and design techniques.
Future Facilities’ 6SigmaDCX software suite allows users to analyse the impact of external environmental factors, including wind profiles, humidity, solar gain and even exhaust emission contamination from generators. This proved to be invaluable for Red Engineering, when designing a state-of-the-art rooftop plant for a Tier III 40,000 ft2 data centre.
The company used VF to predictively simulate the impact on the facility’s operating conditions. As a result of doing so, it was able to safely instigate a significant redesign that safeguarded the cooling plant’s performance in extreme weather conditions.
With an increasing trend towards more free cooling – either direct (fresh air directly into the data centre) or indirect (fresh air used to cool the data centre air without mixing) – the environment outside a data centre is now more important than ever. The interaction between a building’s intakes and exhausts with the weather outside can greatly impact the successful running of the facility.
Without VF, the consultant cannot easily ensure that the cooling system they have designed will deliver the required load in the operating environment, leaving unanswered questions about the resilience of the facility.
Instead of being reliant on manufacturers’ recommended space requirements (running the risk that the facility would not meet design goals), Red Engineering used VF to understand the complex relationship between white space, external weather and cooling plant.
The site was part-loaded but was reporting data hall supply air of 37°C. VF showed that poor cooling plant layout, combined with specific weather conditions, were the cause. Despite being only 34°C outside, strong winds were causing recirculation of exhaust air, raising temperatures in the roof well beyond 50°C.
The chilled water temperatures rocketed to 28°C, which led to extreme temperatures within the hall. With the problems identified, Red Engineering then used VF to redesign the plant and to deliver safeguarded performance in all weather conditions.
CFD is useful in all geographies – however, in some locations there are additional challenges in terms of pollution for ambient cooling.
Scott Payton, technical director at Global Data Center Engineering, explains that in regions where there are out of control forest fires, such as Indonesia, the wind can suddenly change and the resulting pollution can affect neighbouring countries, such as Singapore.
“There are air quality issues that you will not find in other parts of the world. Humidity is another factor that needs to be monitored in some areas. Everywhere is different, so you need to be able to see how equipment will perform in that environment,” he continues.
Paul Finch, chief operating officer of KAO Data Centres, reports that simulation has played an important role in energy saving cooling innovation at the company’s new data centre in Harlow.
Once completed, the campus will comprise four data centres with four ‘technology suites’, designed over three floors, totalling approximately 150,000 sq ft of technical space. Each technology suite will be capable of supporting a 2175kW IT load totalling an 8.7MW IT load across each building. At the heart of the data centre’s design is an evaporative cooling system, which will result in increased reliability, higher energy efficiency, increased sustainability and lower operating costs over the life-cycle of the facility.
“Although we study trends, and the work that ASHRAE has undertaken, as a wholesale data centre developer, it is impossible to know what customers will employ in terms of IT and networking equipment.
“For many years, we were designing data centres around 1500 W/m2. However, today, customers are asking for higher densities. We are now starting to move towards 3KW/m2. With the loads increasing, there are greater amounts of heat,” Finch comments.
When using an adiabatic cooling approach, CFD gives extra assurances early on and enables the system to be optimised to meet industry accepted cooling recommendations, as well as evaluate whether it is actually necessary to invest in mechanical systems, which can add 25% in capex.
“Data centres cost a lot of money. You need to have a clear understanding of where you are committing your money,” Finch comments.
“You need to be sure that, when it is built, it does what it says on the tin. There is a lot of risk involved but there is also a lot of opportunity. CFD means we can test and be innovative, with low risk and low cost. You can deliver significant benefits over the longer term.
“If you can use CFD to demonstrate what the outcomes are going to be, you can offer customers assurances.”
Using simulation also helps reduce the time to market for cooling innovation – why prototype when you can simulate? Airedale is using the technology to help design cooling equipment.
“To build several different prototypes with different heat exchanger layouts would be impractical, but CFD allows us to explore different concepts early on, in a cost-effective and timely fashion, as well as during the more detailed design phase to identify and mitigate any potential problems that could arise further down the line,” says Patrick Cotton, customer services manager at Airedale International Air Conditioning.
Cotton first gained an insight into the use of simulation while working in Airedale’s R&D team. The company uses Future Facilities’ 6SigmaDCX software suite to help them optimise the design of its state-of-the-art ACUs and chillers. VF addresses the demand for more effective cooling systems by using CFD to simulate airflow. It has improved Airedale’s performance in design stages and enabled the company to build a precise replica of its test facility. For Airedale, this has resulted in better offerings to customers as well as enhanced research and development.
Analysis goes beyond the design of the cooling hardware, however. Cotton comments: “From our perspective, responsibility doesn’t stop at the output of the unit. The [cooling] hardware has to perform within the data centre environment it is placed in… It is critical for the end user to look at how the air travels through to the IT equipment. The software provides a lot more value; we can advise customers on best practices and help them meet guidelines,” he comments.
Mitigating human error
Human error is another area of uncertainly where virtual reality may be able to help in the future, according to Payton.
“The data centre industry is where the aviation industry was in 1970. In 1970, aircraft moved away from traditional prop engines and there was an expectation that the number of fatal crashes would decrease – they had spectacular redundancy and more reliable engines.
“However, between 1970 and 1980, the number of crashes didn’t go down. Redundancy did not solve the problem,” comments Payton.
He points out that more than 70% of data centre failures are caused by human error. The aviation industry, however, has improved its record and the use of simulators has made a difference.
Pilots can practise for possible failures, over and over, throughout the span of their careers, so they are ready for any eventuality. Payton hopes that the data centre sector will adopt the same approach.
“This could have a serious impact on outcomes and reliability for data centres in the same way simulation has helped the aviation industry,” he concludes.