Green Cooling Strategies

Liquid cooling is evolving as a foremost alternative to traditional air-based systems, offering faster heat dissipation through direct-to-chip cooling and immersion cooling methods. AI-driven cooling management enhances efficiency by analysing real-time data to adjust cooling systems and predict maintenance needs.

As data centres evolve to meet rising demand, innovative cooling technologies have become essential for improving energy efficiency and managing costs. Green and energy-efficient cooling solutions for data centres focus on reducing energy consumption and minimising environmental impact. The approaches for optimising data centre cooling include free cooling and liquid cooling systems, which use water or refrigerants to remove heat, reducing dependence on air conditioning.

AI-driven optimisation has a role in monitoring and adjusting cooling systems for peak efficiency. Further, renewable energy sources reduce carbon footprints. The scalable designs enhance performance by aligning cooling capacity with current needs, minimising waste. As data centres evolve to meet rising demand, innovative cooling technologies have become essential for improving energy efficiency and managing costs. Shyam Lodh, CEO of Vcom Technologies, highlights the increasing pressure on data centres to optimise power usage due to the rise of cloud services, IoT devices, AI, and big data.

Technologies for data centre cooling

The rising heat generated by CPUs and other components, driven by rising data loads and storage demands, requires heat rejection solutions. Alexandre Kontoyanis, Technical Director of MC LATAM, notes that two cooling technologies, direct liquid cooling (DLC) and immersion cooling, are gaining traction. Both have pros and cons with the fast pace of technological change, and today’s solutions might differ from tomorrow. DLC technologies are advancing, with better cold plates and improved capacity, while immersion cooling is progressing even faster. However, immersion cooling presents challenges, such as the need for server modifications, since manufacturers like Dell do not sell servers designed for immersion cooling. This requires data centres to adapt servers by removing fans, updating firmware, and making other adjustments, which can be difficult.

As 2024 brings over 100 new DLC products, adopting these technologies becomes essential, especially as DLC continues to dominate the market. Immersion keeps growing as the density of the racks rises; that is the trend. And the potential reality of quantum processors could completely reshape the cooling landscape.

In India, data centres are an emerging segment. Kallul Datta, South General Manager at Trane Technologies, observes that the rise of generative AI is propagating data centres to move away from traditional cooling methods towards more advanced, technically driven solutions. Free cooling is still in demand for HVAC systems, including chillers, but data centre operators are looking for low-cost designs. While free and liquid cooling has their advantages, the choice depends on the specific needs of the data centre. Liquid cooling, for instance, is ideal for high-density deployments that require independence from climatic conditions, though it comes with potential leakage risks and simple maintenance requirements. However, the success of a cooling system depends on the size and criticality of the data centre’s operations.

Fans improve thermal management

Another aspect of air cooling data centres is the fans’ efficiency. Optimal fan performance plays a role in maintaining thermal management. Prashant Gore, Manager of Engineering & Application at Ziehl-Abegg India, emphasises the importance of energy-efficient fans to optimise airflow and improve thermal management in data centres. Given the fluctuating loads within data centres, the placement and operation of a fan in a data centre are crucial for optimal performance. Variable-speed fans with EC motors can adjust to changing requirements without compromising efficiency, and fans integrated with AI or advanced control systems can further enhance performance.

Improving thermal management is also crucial. The choice of fan technology should be tailored to the specific needs of the data centre to ensure optimal efficiency.  

Arvind Singh, Director of Tech & Strategic Sales at FläktGroup India, observes that data centre designers are increasingly aligning HVAC systems with IT equipment cooling needs. While innovative cooling technologies are emerging, most facilities still rely on air-cooled or water-cooled chillers with Fan Wall Units. However, maintaining high airflow velocities and noise remains a challenge.

Ashok Yadav, Product Manager for Thermal at Vertiv, adds that as technology advances, data centre designs incorporate fluid mechanics rather than new components like heat exchangers, which may need to be more visible in future designs. Big data centres, often housed in single buildings, will face space constraints, particularly for chiller placement, necessitating changes in air cooling strategies. AI is to bring a significant change every three to four years, and companies must stay ahead of the curve and adapt to these changes.

Free cooling vs. hybrid cooling

Free cooling utilises external environmental conditions, like cold air or water, to cool data centres. This approach is becoming increasingly popular in colder climates, where outside air can effectively chill server rooms with minimal mechanical assistance.

There are two primary methods of free cooling. Airside economisation involves bringing in outside air and expelling warm air from the data centre, which decreases reliance on mechanical cooling systems. Conversely, waterside economisation employs chilled water or liquid to absorb heat from the data centre, often leveraging naturally cold sources such as lakes, rivers, or the ocean. While implementing free cooling can lower energy costs and reduce carbon emissions, it necessitates careful planning to avoid contamination and condensation issues.

Free cooling is highly effective when ambient temperatures are favourable. According to Kallul Datta, modern chillers with free cooling capabilities activate based on the data centre’s return water temperature and chilled water demand. Free cooling helps reduce energy consumption more efficiently than liquid cooling. However, with AI advancements, the industry is shifting from free cooling to conventional cooling, eventually towards liquid cooling. Today, 70 percent of data centres still rely on free cooling, but liquid cooling is rapidly gaining popularity due to increased data centre size and density. Hybrid cooling systems, combining different cooling technologies, are expected to dominate the data centre market.

Liquid-Air hybrid systems

Hybrid systems integrate liquid and air cooling methods to optimise cooling efficiency across various areas of the data centre. Typically, these systems utilise liquid cooling for high-heat components, such as processors, while employing air cooling for less heat-intensive elements. By striking a balance between cost and efficiency, hybrid systems present a compelling solution for facilities moving toward higher-density operations.

The choice between free and liquid cooling in data centres depends on favourable climatic conditions. Free cooling offers high energy efficiency, reaching 70-80%, while liquid cooling offers lower costs, frequent use, and compatibility with temperature and climatic conditions. Both options are simple to design and install, making it difficult to determine which is better. The decision ultimately depends on the data centre player’s needs, the type of data centre they plan to set up, and the investment they plan to make.

AI-driven optimisation of cooling systems

AI-driven optimisation improves the performance of cooling systems by monitoring parameters.  Artificial Intelligence and machine learning algorithms optimise cooling systems in real time. By analysing data from temperature sensors, airflow, and other environmental metrics, these AI-driven systems continuously adjust to enhance efficiency and lower the overall power consumption of cooling units. Moreover, AI facilitates predictive maintenance by anticipating equipment failures and suggesting maintenance schedules before issues arise, thus preventing downtime.

Another advantage of AI-powered systems is Smart cooling automation, which adjusts cooling capacity based on server loads. It helps prevent both overcooling and undercooling, resulting in substantial energy savings. With the increasing integration of AI into IT workloads, AI is also essential in optimising cooling infrastructure and managing its efficiency. Looking ahead, AI-enabled cooling units will be widely available, offering even higher levels of efficiency. These systems will learn and adapt to customer requirements, ensuring optimal performance. AI is a key component in cooling solutions across the industry.

Innovations in cooling systems include solar and wind power, as data centres invest in renewable energy to operate these systems. Geothermal cooling is another effective method, utilising underground temperatures to cool data centres naturally, especially in areas with accessible geothermal resources. Water conservation techniques are implemented, such as using seawater or wastewater for cooling instead of freshwater, further minimising the environmental impact of cooling operations. Data centres are going for sustainability, exploring renewable energy sources and eco-friendly cooling methods to reduce their carbon footprint.

Compliance standards

Compliance standards around environmental sustainability are becoming drivers of global innovation, with regulations in Europe and the US preferring these issues. Ashok Yadav highlights that India’s guidelines, which include a ban on HFCs by 2032, may influence other regulatory bodies, ensuring compliance within the country. Kallul Datta notes a growing demand among data centre operators for cooling equipment with very low Global Warming Potential refrigerants for chillers. HFCs have largely been phased out in data centres, with ultra-low GWP refrigerants, such as HFOs, gaining popularity due to their energy efficiency and environmental benefits. Sustainability commitments and carbon management are major concerns for data centre clients. It is expected the industry will transition from HFC to HFO-based products shortly.

Prashant Gore adds that while Europe and the US have energy regulations that mandate highly optimised fans for condensers and chillers, India currently lacks specific standards for these devices. However, companies are still offering compatible solutions for both indoor and outdoor applications to align with these global standards.

With the growing demand for data centres, the need to enhance energy efficiency and sustainability will propel the adoption of innovative cooling technologies. Examples of this evolution include liquid cooling, AI-driven optimisation, free cooling, and hybrid systems. In the future, sustainable cooling practices and modular systems will shape data centre infrastructure, ensuring that the digital backbone of our society operates effectively and responsibly.

Data centre operators should proactively adopt these technologies to maintain a competitive edge in an environmentally aware market.

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Mr. Prashant Gore, Manager- Engineering & Application, Ziehl-Abegg India Pvt. Ltd.

Energy regulations in Europe and the US mandate highly optimised fans for condensers and chillers, whereas India currently lacks specific standards for these devices.

Mr. Alexandre Kontoyanis, Technical Director, MC LATAM.

DLC and immersion cooling are two emerging trends, with perpetual growth in DLC technologies.

Mr. Ashok Yadav, Product Manager Thermal, Vertiv.

AI is expected to drive advancement every three to four years, and companies must stay ahead of the curve and adapt to these changes.

Mr. Kallul Datta, South General Manager, Trane Technologies.

Free cooling in data centres is more effective in reducing energy consumption than liquid cooling.

Mr. Shyam Lodh, CEO, Vcom Technologies

With cloud services, IoT devices, AI, and Big data expansion, data centres are under immense pressure to optimise power usage and cooling performance.

Mr. Arvind Singh, Director- Tech & Strategic Sales, FläktGroup India.

The rise in high-density racks is driving the adoption of Fan Wall Units, providing efficient cooling by handling higher heat loads with increased airflow and velocity.