Flicking the switch - exhausted efficiency gains within your data centre design?

The fact that the data centre sector is one of the largest consumers of energy is no secret and governments around the world are ramping up pressure on it to lower its carbon emissions. While the focus has been on adopting measures such as more efficient cooling systems, renewable energy and heat reuse, as well as constructing facilities in regions with either colder climates or with the ability to harness hydroelectric power. Attentions are also turning towards other, perhaps less obvious elements of data centre infrastructure where operational efficiencies can, and should, be made.

Under the spotlight

Responsible operators take their sustainability based obligations extremely seriously, while striving to deliver resilient infrastructures that consumers and businesses expect for supporting their increasing internet usage. This is just as well, as in 2020 the European Union (EU) Green Deal suggested that data centres ‘can and should be carbon neutral by 2030’. To meet this challenge, over 20 leading data centre companies and cloud infrastructure providers, along with trade associations from across Europe, recently joined forces to form the Climate Neutral Data Centre Pact (CNDCP).

With the ‘low hanging fruit’ already being addressed, the challenge to lower Power Usage Effectiveness (PUE) ratings by looking into other areas of a data centre’s operation are increasing. Despite the advantages offered by LED technology and lighting management systems, data centres have traditionally been slow to adopt them. Perhaps because lighting only comprises 3-5 per cent of a facility’s energy load, some data centres simply haven’t had it on their radars. However, they will need to refocus if they expect to thrive in the long-term.

The bigger picture

Reducing both short and long-term capital and operational expenditure (CapEx and OpEx) relies upon looking at a data centre as a whole – how they operate and what’s housed within. Installing an intelligent lighting system comprising of LED panels, tubes, battens and high bay lighting devices that are flexible, easy to install and future proof will ensure that they last for many years, however, to gain real efficiencies it’s also important to take into account the overall design and distribution of light.

We are some way from truly ‘lights-out’ data centres, so providing area specific task lighting precisely when and where it is needed is an important design consideration. A lighting management system can therefore prove beneficial and energy savings of an additional 10-15 per cent are possible when luminaires are integrated with sensors to manage how, when and where light is used. Just as significantly, lighting must be specific to a particular aisle layout, so installing luminaires that offer enhanced vertical illuminance means intensity can be focused on the task area (face of server racks and cabinets) rather than over lighting the floor to reach the desired vertical lux levels. In addition to enhanced vertical illuminance adopting the appropriate lens technology for the area helps create a safer, more efficient work environment, enabling data centre technicians to carry out changes, maintenance and upgrades to servers quickly and accurately.

Lighting infrastructure must also be able to withstand specific environmental conditions often found within a modern data centre. The use of LED luminaires and lighting systems that are tested and approved to operate within higher ambient temperatures is a must – this not only lowers the running costs of the lighting system when compared to traditional compact fluorescent lighting technology, it also operates seamlessly in higher ambient temperatures supporting the drive to reduce data hall cooling, which in-turn plays an essential role in achieving a low PUE rating.

Boxing clever

A lighting design strategy should be considered in relation to other data centre components. For example, the colour of cabinets and racks has a direct impact on energy consumption, this is where the light reflectance value (LRV) comes in. LRV is the total quantity of visible and useable light reflected by a surface in all directions, and at all wavelengths, when illuminated by a light source. Essentially, it tells you how much light a colour reflects and/or absorbs.

The LRV scale runs from 0-100 per cent. In practice, the average blackest black has an LRV of five per cent and the whitest white 85 per cent, so above the 50 per cent mark more light is reflected than absorbed. To put this into context, white RAL 9300 has an LRV of approximately 83 per cent, so the amount of reflected light means that a data centre could use fewer luminaires with a lower connected load than it would with black cabinets and racks, whilst maintaining the required lux levels. Zumtobel research has found that savings can be realised throughout a whole data centre’s lifecycle simply by taking in to account various environmental factors. In fact, the energy consumed and the number of luminaires installed within a data hall lighting system could be reduced by up to as much as 37 per cent. See our full study here.

Although they still represent a small proportion of the overall number installed, the use of white cabinets and racks is now recommended best practice. The EU Code of Conduct for Data Centres (Energy Efficiency) states, ‘Use pale/light colours on walls, floor fixtures and fittings including cabinets etc to reduce the amount of lighting required to illuminate a data hall and therefore the energy consumed in lighting. This will also ensure good levels of visibility both throughout the hall and within cabinets, creating a better lit environment and therefore improved life safety’.

Safety first

We can be under no illusion about the absolute necessity of keeping data secure and being alert to all the potential risks posed. But such risks are not just about the potential for cyberattacks – natural disasters, vandalism and terrorism can all lead to downtime, so implementing measures that minimise the chances of any physical attack occurring should be a high priority for data centre operators.

Security should take a multi-layered approach and include high grade perimeter fencing, obstructions such as anti-ram bollards and vehicle monitoring, as well as thorough access control procedures. As part of a security strategy, high quality external lighting can help to fortify a facility’s defences. Illuminating the outdoor space surrounding a data centre also provides a sense of safety for employees and visitors. It can also help with wayfinding, as a lighting design can shape and define the perimeter of a space, whilst providing guidance from one part of a campus to another.

Life safety is also important, so a data centre must have a robust and reliable addressable emergency lighting system in place. Data centres can present challenges in terms of battery life due to high ambient temperatures, so the recommended central battery systems, can be located in a plant room where temperatures are either naturally lower or cooled to around 20°C. As well as enhancing battery life, this also reduces maintenance time, maintenance frequency, physical interaction within the data hall and costs.

Every little helps

Increasing energy efficiency, lowering their carbon footprint and reducing operational expenditure continue to be key objectives for data centre Operators. This does not stop at purchasing renewable energy, investing in solar and wind power and implementing the latest cooling technologies – it also means looking at how innovative lighting solutions can help to make data centres more sustainable, while minimising maintenance and maximising security. In order to achieve the most appropriate lighting infrastructure, it is advisable to engage with a solutions provider that has proven expertise in this area and understands the competitive advantages of data centres that are fully energy optimised, automated and environmentally friendly.

Zumtobel recently completed a data centre lighting study to understand the impact cabinet and rack colour, as well as lens technology, have on CapEx, OpEx and the ability to carry out tasks. To support this research it has developed a Data Hall Virtual Reality Experience to demonstrate the key findings in an immersive and interactive format. To find out moreand to arrange a private virtual experience please visit https://discover.zumtobelgroup.com/data-centre