Sustainable Cooling Technologies for Data Centres

The world will come to a halt, with countries bearing millions of losses if cyberspace comes to rest even for a day. While data consumption is rising and the world is running over the internet, the emphasis on data centres is at its peak. The global soaring temperature makes us note that the temperature of centres where huge amounts of data are stored is also maintained for smooth functioning. Industry experts share their bits about the problem, its solution, and a better future.

With their intricate technological setups, data centres demand vigilant monitoring and management for safe and efficient operations. A critical aspect of this oversight is ensuring optimal temperature levels. Elevated temperatures and humidity within a data centre can lead to condensation, posing a serious threat to the equipment. The potential damage and disruption caused by such conditions underscore the imperative to prevent them at all costs. Fortunately, available technologies are designed to effectively maintain and regulate data centre temperatures.

Emerging Trends
Amod Ranade, Vice President and General Manager – Asia Pacific, Green Revolution Cooling, says, “We are witnessing a shift in the types of applications data centers are accommodating. High-performance computing is on the rise, fueled by government initiatives like the National Supercomputing Mission, which aims to equip educational facilities with supercomputing capabilities. These technologies demand high-density server clusters, posing a challenge in terms of computing density.”

There is a growing emphasis on enhancing energy efficiency, with the Power Usage Effectiveness (PUE) metric playing a crucial role in data centre strategies. This is especially pertinent for companies whose core business revolves around data centres, known as colocation or hyperscale data centres. A lower PUE directly impacts their bottom line, and governments are beginning to enact regulations in response to the rapid expansion of data centre infrastructure. For instance, in Singapore, laws dictate that data centres cannot expand or be built without a commitment to a specific PUE.

Sustainable cooling technologies
Data centre cooling is witnessing a surge in innovations with the formidable challenge faced by data centre owners in the cooling domain. Three distinct approaches are prominently shaping this landscape. The first involves optimising air utilisation through technologies like containment systems. This ranges from cold containment to hot air containment. Different air-handling unit architectures have emerged over the past decade, transitioning from raised floor cooling to in-row cooling and innovations like fan walls, where entire walls serve as air-handling units, dispersing air into the data centre.

Simultaneously, there is a wave of innovation in cooling mediums. While single-phase liquid immersion cooling has gained attention, alternatives such as water or water mixed with ethanol are making strides. Direct liquid cooling, also known as cold plate liquid cooling, and the historical concept of water on chip from the 1970s have resurfaced. Despite the associated risks of potential leaks and failures, some server solutions involve water running on the motherboard. Additionally, two-phase liquids are entering the scene, claiming to capture more heat due to low-temperature boiling and the latent heat of evaporation, creating a cyclical process.

Kapil Kapoor, Founder-CTO, Vayuguard Climate Tech, shares that the industry is calling for hybrid solutions in technology advancements, with a notable shift observed as some major MNCs are increasingly opting for these alternatives. It is anticipated that many data centre owners will transition from traditional setups to hybrid systems within the next four to five years.

Hyperscale data center
Mr. Ranade mentions that the significant catalyst for global data centre expansion is the rise of hyperscalers. The demand surged notably during the initial lockdowns, revealing a rapid shift towards online activities that were previously unimaginable, such as remote teaching and learning. This increased reliance on remote work has become a growing trend, driving the need for cloud-based systems. Major multinational companies like Microsoft, Amazon, Zoom, and Salesforce are adapting to this shift, offering their solutions as service models delivered through the cloud.

In the Asia Pacific region, where the focus is on connectivity to the Internet, there has been a remarkable uptick in demand for hyperscale capacities. Countries like India, Singapore, Malaysia, Indonesia, and Thailand are witnessing substantial growth in data centre infrastructure. Hubs like Mumbai and Chennai have become key data centre centres equipped with landing stations for undersea cables. The availability of skills, energy, and a customer base further contributes to the momentum, with hyperscalers playing a pivotal role in propelling this growth.

Leak Challenge
The unique properties of the coolant involved address concerns about potential leaks in liquid immersion cooling. In single-phase liquid immersion cooling, the coolant is a dielectric fluid, essentially an electricity insulator. When servers are immersed in this liquid, there is no risk of short circuits, ensuring the safety of IT equipment even in the event of a leakage.

The design of the liquid immersion cooling system minimises the risk of leaks. Unlike high-pressure or high-velocity hydraulic systems prone to bursting pipes, this system operates at low pressure and is open rather than closed, with the tank exposed to the air. These factors contribute to a shallow risk of any leakages. The retrofit of liquid immersion cooling into existing data centres is also a viable option.

Precision air conditioning
The future of precision air conditioning in data centres is evolving rather than being completely overshadowed by liquid immersion cooling. The trend suggests a rise in hybrid data centres, as liquid immersion cooling effectively addresses the challenges of server density and extreme clusters. At the same time, precision air conditioning remains pivotal for managing storage and networking components.

Although liquid immersion cooling could theoretically extend to network and storage equipment, current industry preferences lean towards using this technology primarily for servers within data centres; the critical advantage of liquid immersion technology is the added benefit of corrosion protection for coated servers, as the coolants create a preventive layer against environmental elements like SO2 and NO2.

Data Localisation
Umesh Kale, Business Unit, Manager- HCT, Munters India Humidity Control, contributes, “The decision regarding data localisation depends on several factors. It may be the regulatory framework in place, the complexity of data setup for an organisation, and the trade-off between data protection and cost considerations. Expanding data centre capacity could lower the costs of local data storage. This encourages greater adoption of data localisation. However, organisations should exercise caution and thoroughly assess their requirements and the regulatory environment. It is necessary before committing to data localisation strategies, especially in the context of data security.”

Al and Machine Learning
The prevailing trend in the industry sees a significant focus on leveraging AI for end-use applications, particularly in fields like legal and medical services. Researchers are exploring the possibility of transferring tasks that typically require human cognition to trained AI engines, paving the way for increased automation even in decision-making processes.

Mr. Ranade, while citing his two decades of experience, reminisces about many initiatives exploring AI systems, such as real-time Computational Fluid Dynamics (CFD) views to predict and prevent hotspots through proactive cooling modulation. While these endeavours have yet to materialise into launched data centre applications, the use of AI engines for optimising HVAC in comfortable cooling environments has gained traction.

Mr. Kapil says, “Many HVAC systems now leverage AI and machine learning for data collection and analysis, providing predictive insights based on current or gathered data. For instance, in corrosion prevention equipment, real-time monitoring captures and stores data, allowing for analysis to determine when filters need replacement. Mechanical filtration, whether chemical or absorption-based, requires periodic replacement, and sensors play a crucial role in life cycle analysis.”

Data Center Corrosion
Data centres used lead coatings on contact points in the past, but this was prohibited due to environmental concerns. Nowadays, they use metals like silver and copper, which are susceptible to corrosion if the environment is not optimal.

Four main factors contribute to the corrosion of data centre equipment: hydrogen sulfide, sulfur dioxide, bromine, chlorine, and nitrogen oxides (NOx and SOx). Corrosion can be particularly detrimental to printed circuit boards (PCBs) and contact points, which have become smaller in modern data centres. PCB failure can result in significant financial losses for IT companies due to data loss and the need for equipment replacement.

To address this issue, industry standards, such as ISA standards, specify different grades (G1, G2, G3, GX) that data centres should maintain. G1 is mild, while G2 and G3 are more stringent. Various testing methods, like online monitoring and coupon testing, are used to assess and maintain these standards.

Design considerations for data centres include room pressurisation, air circulation, temperature, humidity control, and sealing to prevent gas infiltration. Ensuring gas-tight environments is crucial in areas with high air pollution, like Delhi and NCR.

There are several solutions available to protect data centres from corrosion. Many companies offer gas-phase and chemical-based filtration systems to safeguard equipment. Coatings like perylene and anodising are used for PCBs. Real-time monitoring and coupon testing help track corrosion levels and adjust filtration efficiency. Mechanical-based filters need periodic replacement, making monitoring critical to ensure data centres comply with the desired standards.

Environmental challenges
The major concern lies in the environmental impact of the mediums used, as evidenced by stringent regulations addressing ozone depletion potential. Despite their technical capabilities, refrigerants and cooling mediums with harmful environmental effects have been phased out. Another notable challenge is energy consumption, particularly in data centres where infrastructure comprises electrical and cooling systems. Unlike electrical systems with minimal losses, cooling systems consume energy that doesn’t contribute to IT operations, constituting nearly 50% of infrastructure energy usage.

Mr. Ranade highlights the sustainability and “greening” of operations, which are influenced by the attributes of the cooling system and the associated maintenance regime. Proper disposal solutions for alternative cooling mediums are crucial in minimising environmental pollution during equipment scrapping.

The impact of environmental challenges in cooling systems varies based on the predominant source of electricity. In India, the primary source remains thermal power stations, relying heavily on coal-fired electricity. Despite strides in renewable energy, coal-fired power remains dominant. Given the reliance on coal-fired thermal power, every kilowatt saved in a data centre directly reduces carbon emissions.

Government regulation
Mr. Kapoor cites that global benchmarks such as WHO, RESET, and WELL standards are being adhered to for IAQ in the absence of current local regulations. On the corrosion front, standards exist for space conditions, categorised into G1, G2, G3, and GX grades, assessing corrosion on copper and silver plates. Sensors placed in these spaces provide resistivity data, enabling analysis of the corrosion impact and adherence to global standards, as India currently lacks specific policies for IAQ and corrosion.

Mr. Ranade says, “The government’s initiatives in collaboration with the Bureau of Energy Efficiency and the Indian Green Building Council are a source of optimism. Key contributions have been made to initiatives such as the revised data centre design guide, emphasising metrics like Power Usage Effectiveness (PUE) and promoting energy efficiency across data centre infrastructure, where cooling plays a crucial role. While regulations may not mandate efficiency, the economic incentive is substantial, given that 80 percent of the operating expenses of the data centre are attributed to electricity bills throughout its lifecycle. This commercial consideration becomes a driving force for operators to prioritise efficiency and save costs. Collaborative efforts with agencies like the Bureau of Energy Efficiency and the Indian Green Building Council continue to shape the industry by promoting more efficient options, particularly in the cooling domain.

=========================

Dr. Vijay Chaudhry, President, Bry-Air
“Managing the heat produced by data centres enhances energy efficiency while addressing environmental concerns.”

Umesh Kale, Business Unit Manager- HCT, Munters India Humidity Control Pvt. Ltd.
“Split system cooling is best for temperature control in cases where data centres face environmental pollution and fluctuating humidity.”

Amod Ranade, Vice President and General Manager – Asia Pacific, Green Revolution Cooling”
“A lower PUE directly impacts their bottom line, and governments are beginning to enact regulations in response to the rapid expansion of data centre infrastructure.”

Kapil Kapoor, Founder-CTO, Vayuguard Climate Tech Pvt Ltd
“Maintaining the optimal temperature in data centres is paramount to prevent condensation, which can cause severe damage and disruptions.”