The Future of Data Centre Cooling: Innovations for Sustainability

As technology, internet traffic and power-hungry workloads require more computing resources, the demand for data centres increases. A recent Data Centre Trends 2023 report brought many interesting insights. Chief among them was the overall trend that demand will continue to grow by 15 per cent yearly.

This increased usage brings sustainability concerns. Data centres already use 1.5 per cent of global electricity consumption, making providers a key player in the hunt for net zero. Improving energy efficiency presents many challenges to the data centre industry — but also exciting opportunities for innovation.

At the heart of this challenge lies the implementation of efficient and sustainable cooling solutions. The average modern data centre uses around 40 per cent of its power for cooling. After all, to provide a secure, high-quality service, processors and other hardware must be kept in optimal conditions. The future of data centre cooling techniques must bring methods that remove this excess heat in a more environmentally friendly way.

In this blog, we’ll examine the range of cooling technologies currently employed within the industry. We’ll dive into each method, analysing its advantages against potential limitations. Then, we will look at cutting-edge data centre cooling — how manufacturers at the height of innovation are championing sustainability whilst addressing high-performance computing demands. Let’s get started.

Data Centre Cooling Methods and Systems

Modern data centres handle a wide range of traffic, enabling everything from financial transactions to social media interactions. As this demand means data centres grow in scale and complexity, the importance of efficient cooling solutions intensifies.

There are several common cooling methods in use today. There are also many promising new techniques in the pipeline. Ensuring these systems are efficient, reliable and sustainable is perhaps the key challenge for data centre providers. Below, we dig into some of the most prominent cooling methods, looking at their respective strengths and weaknesses.

Air Cooling

Air cooling uses air conditioning, fans and vents to circulate ambient air, expelling the hot air produced by computing equipment. It's the most traditional method and forms the basis for many data centre cooling strategies.

Advantages of air cooling in data centres:

• Generally reliable performance levels and suitable for various data centre types
• Proven technology with a history of effective air temperature management
• Easily implemented in both small and large-scale facilities

Disadvantages of air cooling in data centres:

• Potential for high energy consumption, especially for facilities in warmer climates
• Dependence on airflow can cause fluctuations in energy usage
• Can bring high energy costs if not managed effectively

Liquid Cooling

Liquid cooling technologies have emerged in recent times as a popular solution, with almost 40 per cent of data centres employing it in some way. Liquid cooling systems use coolants that circulate through a pipe network, absorbing heat away from IT equipment. They can be especially effective for cooling high-density servers.

Advantages of liquid cooling in data centres:

• Can typically offer superior heat removal compared to air cooling
• Uses the conductive properties of liquids to quickly move heat away from servers
• Particularly effective for high-power density facilities

Disadvantages of liquid cooling in data centres:

• Can use vast amounts of the local water supply.
• Coolant leaks can be environmentally unfriendly if not addressed properly
• Complex to set up and can have several potential points of failure

Spotlight on Digital Realty's Direct Liquid Cooling

Earlier this year, Digital Realty launched a cloud and carrier-neutral Paris centre, emphasising energy efficiency. Addressing data gravity concerns, the La Courneuve hub incorporates direct liquid cooling, focusing on performance needs while minimising Scope 1 and 2 emissions. This cutting-edge liquid cooling solution guarantees optimal energy use and brings economic advantages for clients.

Immersion Cooling

With immersion cooling, IT components are directly submerged in dielectric fluids that cool by absorbing heat. Servers are kept in non-conductive, absorbent fluids that provide effective heat management.

Advantages of immersion cooling in data centres:

• Direct cooling can allow for highly efficient temperature management
• Reduces the reliance on other cooling infrastructures like fans
• Has the potential for significantly reduced energy consumption

Disadvantages of immersion cooling in data centres:

• Might not be suitable for all types of data centres
• Brings potential risks associated with leaks
• Costly and tricky to implement

Evaporative Cooling

Evaporative cooling uses fans to draw outside air in, cooling before deploying it to cool equipment. By using the natural phenomenon of water evaporation, this method draws heat away from the air in an efficient manner.

Advantages of evaporation cooling in data centres:

• Offers reliable cooling when used in appropriate climates
• Can be more efficient than traditional air cooling in specific conditions
• Uses water instead of coolant liquids

Disadvantages of evaporation cooling in data centres:

• Performance can decrease in the wrong conditions
• High dependence on water availability and quality
• Can require an overhaul of existing data centre infrastructure

Free Cooling

This system capitalises on external conditions, primarily cooler outside air or water. Cooling data centres using free air bypasses traditional cooling mechanisms when external conditions make it possible.

Advantages of free cooling in data centres:

• Provides effective cooling when external temperatures are favourable
• Removes the need for mechanical cooling, bringing massive energy savings
• Uses natural resources, minimising carbon footprint

Disadvantages of free cooling in data centres:

• Limited to regions with colder climates or cold seasons
• Variability in external conditions can affect performance
• May require backup cooling solutions in case of unpredicted changes

Data Centre Cooling Design and Optimisation

Data centre cooling isn't merely about installing fans and other coolants. It's about balancing design and optimisation, implementing both efficiency and efficacy. Strategic design combined with optimisation ensures that IT equipment can function without overheating while reducing environmental impact.

Below are some important factors for optimising data centre performance.

• Hot/cold aisle containment: By configuring server racks in alternating rows — with cold air intakes facing one way and hot air output on the other — data centres can create hot and cold ‘corridors’. This maximises efficiency by ensuring cooled air is where it's needed most, while preventing the mixing of hot and cold air.
• Airflow management: By optimising airflow through vents and barriers, data centres can minimise areas of stationary air. Proper airflow management lowers cooling costs by reducing the need to compensate for warm spots. It also helps ensure that cooling is constant throughout the facility.
• Working inside safe limits: Modern IT equipment is actually quite resilient. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) publish temperature standards that give safe operating conditions for common equipment. In some cases, maintaining a slightly warmer temperature — if safe — can save considerable energy.
• Preventing downtime: Internet of Things (IoT) devices, machine learning and automated systems can help data centre operators spot problems before they happen. By monitoring systems and installing timely patches and upgrades, facilities can prevent downtime and improve efficiency further.
• Humidity control: Finally, managing humidity is crucial. Too much can lead to hardware damage, while too little can create damaging static electricity.

Data Centre Cooling Manufacturers and Solutions

The data centre cooling market is vibrant and ever-changing. Manufacturers are investing not just in improving today's solutions, but also in pioneering sustainable technologies for the future. Below, we look at some of today's most popular and innovative cooling providers.

Schneider Electric: Schneider Electric's cooling solutions are renowned for their efficiency and come equipped with IoT features. This allows for predictive maintenance and optimal performance.

Iceotope: Iceotope brings novel immersion cooling technologies that can transform data centre performance. Applicable to traditional, hyperscale and edge computing environments, Iceotope’s technologies can help implement notable improvements in power usage effectiveness (PUE).

Stulz: Stulz is known for their careful temperature and humidity control initiatives. By using free cooling, Stulz helps data centres minimise energy consumption and reduce CO2 emissions.

Vertiv: Creating adaptive and intelligent cooling solutions, Vertiv uses machine learning to enhance cooling efficiency. By continually learning and adapting to a data centre's environment, the Vertiv system ensures optimal cooling, conserving energy and improving equipment longevity.

Spotlight on Digital Realty’s Cooling Tower Initiatives

Data centre operators are likewise innovating to improve cooling efficiency. At its SIN10 facility in Singapore, for example, Digital Realty employs DCI electrolysis for water preservation, saving 1.24 million litres monthly. This process eliminates chemical usage, allowing water to be used three times as long before becoming wastewater. Amid Singapore's escalating water demands, SIN10 has since lowered both water and power usage.

Data Centre Cooling Trends and Future

Looking to the future of data centre cooling, we see several exciting trends that can help further reduce the industry’s environmental impact. Using new technologies and strategic data centre design, for example, could prove vital.

1. Adaptive Cooling: Employing AI with cooling systems promises more adaptability than ever. These solutions continually learn and adjust to the specific cooling needs of each data centre in real-time — reducing over-cooling and energy waste.
2. Edge Data Centres: We could see even more data centres placed in strategic 'edge' locations in the future. These edge centres ensure low-latency data delivery and introduce innovative cooling possibilities in their unique settings.
3. Sustainable Energy: While it’s vital to become more efficient at energy management, it’s also possible to use energy from renewable sources. Solar or wind-powered data centres, for instance, are no longer a dream but a reality. Combining renewable energy sources with efficient cooling strategies presents a holistic approach to sustainability progress.
4. These innovations and changes, coupled with advanced cooling techniques, can help make future data centres increasingly energy efficient.

The Future of Data Centre Cooling Solutions: Key Takeaways

Various cooling systems are available in modern data centres. Each brings its own unique benefits and potential drawbacks. From traditional air cooling to liquid and immersion technologies, each has the power to help the global data centre ecosystem reduce its energy and water consumption.

No matter which system is used, one thing remains true: Efficient data centre design, grounded in best practices, amplifies cooling systems’ effectiveness. Manufacturers are looking to nature and technology for green innovations, ensuring that future data centres don't just deliver an excellent service — but do it sustainably.

Learn more about Digital Realty’s ESG goals, or contact us for further information.

systems for temperature and humidity control are also becoming common as data centres become more sustainable.

Frequently Asked Questions (FAQs)

What is data centre cooling?

Data centre cooling refers to the methods and technologies used to maintain optimal temperatures for IT equipment. It helps ensure efficient performance and prevents overheating, which can damage resources and degrade performance levels. Cooling techniques are increasingly vital to reducing data centres’ environmental impact.