Demystifying data centre cooling

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Published: 23 January 2017


data centre cooling
Data centres are at the heart of a business and must be kept running at all costs
expert sales temperature cooling
Richard Metcalfe of ICS Cool Energy
With virtually every aspect of the commercial world reliant on information being transported and stored electronically, server rooms and data centres have fast become the beating heart of global communications. Here Richard Metcalfe, Sales Director at temperature control specialists ICS Cool Energy, discusses the varying ways heating and cooling engineers can get to grips with data centre cooling, and help keep their customers’ systems running in both a cost and energy-efficient way.

There’s no escaping the fact that data centres form a critical part of business infrastructure for a wide variety of market sectors. Ensuring they remain operational no matter what is a major challenge, and one that is quite different to those usually faced by temperature control contractors.

​Many facilities and IT managers often fall into the trap of striving for continual performance and paying over and above what they need to for energy, so it is the contractor’s responsibility to ensure they have the most appropriate cooling system in place which won’t cost the earth. 
Given the volume of electrical equipment often housed in data centres and server rooms, combined with the heat they generate and the tendency for data centres to be remotely located in the depths of a building in confined and secure spaces, the biggest performance-critical application that must tackled is cooling.

However, delivering cooling that will provide the optimum working temperature required for data centres – between 21-25°C – regardless of external seasonal temperature changes, can come at a huge cost to the end user if energy consumption is not closely monitored, given the volume of cooling needed. 

Going back to basics
First and foremost, it is important take a step back from the installation and gauge a few key factors that will ultimately impact the cooling system used. First, where is the data centre located – is it underground, and if so, how far? Next, how big is the available space – is it a new-build project where dedicated space for a cooling system can be incorporated in the design stage, or will it be a retrofit or renovation project where space is limited? Finally, what existing cooling system is the building, and therefore the data centre, connected to? All these factors must be considered before commissioning a system. 

Making the right choice    
Given the high energy consumption often associated with data centre cooling, getting the cooling system spot on during the specification and installation stage can save the end-user enormous amounts of money in the long run. Instead of straightaway choosing a mechanical chiller-based cooling system, I would recommend considering a solution which incorporates ‘free cooling’. Free cooling is especially effective in the UK given the cooler environment, as the technology works by using lower ambient air temperatures to chill the process water, instead of solely relying on mechanical cooling from a chiller. There are three types of free cooling solution that would benefit a data centre, however that decision must take into account the previously discussed factors. 

The first would be to use an air handling unit. This would represent a cost-effective solution if the overall building uses a central air handling plant. The air handling unit effectively takes air from outside the building, reduces the temperature to the level required, and delivers the cool air directly to the data centre. If the external air temperature is below 12˚C – as is often the case in the UK – then the air handling unit itself effectively becomes a free cooling system, as any mechanical cooling required to reduce the air temperature can be de-energised as it is simply not needed. 

A second option would be to invest in an integrated system which uses both a free cooling coil and a chiller unit to provide the cooling. This option would prove useful to those installations where available footprint to support cooling systems is limited, such as when data centres are installed or located within existing buildings rather than new builds. Universities are a classic example, where many older buildings are often repurposed to accommodate growing electrical and digital infrastructure across campuses. With an integrated system, end-users are able to achieve the energy efficiency benefits of free cooling, supported by a chiller when the external air temperature becomes too warm for the free cooling coil to deliver the level required. However, this does mean that mechanical cooling (i.e the chiller) will be needed at times, therefore the overall efficiency rating is not as high as if a fully independent free cooling coil were to be used.

A fully independent free cooling coil is therefore undoubtedly the most energy efficient way of achieving the optimum working environment for a data centre. However, the one drawback which may prevent it being installed in some circumstances is the size. An independent free cooling coil is a large piece of plant, and as such, requires a significant amount of floor space to be installed. If a data centre housing is being designed from the outset, it will definitely pay to accommodate this extra floor space in the long run during the design stage, given the potential energy savings on offer. Yet, it will also unfortunately rule it out as a potential cooling solution for those data centre installations where space is at a premium. 

Going above and beyond for the end-user
Where contractors can really get ahead of the competition and ensure they deliver the most appropriate solution possible for their customers is to undertake a provisional energy analysis programme prior to installation. This involves comparing existing energy consumption (where applicable) with projected consumption of the three varying cooling solutions on offer. The best way to accurately undertake an energy analysis program is to work closely with a specialist temperature control solutions manufacturer – such as ICS Cool Energy – as they will be able to provide an extra level of knowledge and insight to ensure that the most appropriate system is chosen for the customer. 

Final thoughts 
Ultimately, a business’s data centre is the heart of its operations and must be kept running at all costs. Cooling is absolutely critical to maintaining the optimum operational environment and avoiding overheating. However, overly focusing on achieving the correct temperature can leave businesses exposed to unnecessarily high running costs.
To really achieve the best combination of temperature control, efficiency, security and reliability, an all-encompassing approach – inclusive of the contractor, manufacturer and end-user – is the best course of action. Failing to take into account all the risk factors could expose businesses to dangerous downtime, or worse system failure. Invest in a trusted temperature control partner, such as ICS Cool Energy, and you’ll be able to help your customers reap the long-term rewards of successful data centre management.