Playing it cool – the move towards liquid cooling in data centres
As demand for increasingly dense racks and compute-heavy workloads rises within data centres, could this lead to a wholesale shift in preference from air-to-liquid-based cooling systems? Don Mitchell, Data Centre Division Manager at Victaulic, discusses the case for liquid cooling in data centres and why installation is set to become commonplace in the years to come.
Even before the pandemic, digital transformation was well and truly in full swing. In recent years data centres have been packing more and more computing power into smaller spaces to consolidate workloads and accommodate processing-intensive applications, such as AI and advanced analytics. As a result, each rack requires more energy and generates more heat, putting greater pressure on cooling systems to ensure safe and efficient operations.
Liquid cooling vs air cooling
Computer cooling is required to remove the waste heat produced by computer components, to keep components within permissible operating temperature limits. Data centres have mostly used air cooling since their inception and will likely continue to use it extensively. But also liquid cooling is not entirely new, super computers have been using it for decades, and is now gaining momentum. Air cooling is simple to understand and works reasonably well with lower quantities of heat. Many innovations in data centre cooling have greatly improved efficiencies of air-cooled IT solutions, but the facts remain, heat transfers much better with liquid, as air can only carry a fraction of the amount of heat that liquid can.
As heat density increases, liquid cooling becomes the more efficient and effective solution. It enables operators to use higher temperature liquid to keep IT chips at a suitable temperature, while allowing the use of smaller pumps and pipes versus a larger number of fans and ducts. Instead of large volumes of lukewarm air that needs to be chilled with chiller plants or evaporation, smaller volumes of high temperature liquids are produced that only require an air-cooled heat exchanger.
To address efficiency and sustainability concerns, a growing number of cooling vendors are introducing liquid cooled IT solutions. Most data centres plan to change out their IT every three to five years, but it is uncertain how much of the next generation of IT will require liquid cooling. The primary barrier to use liquid cooled IT is lack of familiarity and standardized processes. But here we see changes on the horizon. For instance, OpenComputeProject (OCP) – a global collaborative data centre organization – has launched projects on standardizing liquid cooling technologies and a project on “Advanced Cooling – Facilities” to standardize methods of deploying liquids in data centres.
With proper planning, there are liquid distribution solutions that are both mission critical-ready and adaptable. Deployment of liquid cooled solutions into existing data centres requires solutions that do not require “hot work” – such as welding. They also require precision design and simplistic assembly while remaining reliable, durable and easy to expand. Grooved coupling solutions meet these requirements nicely. Piping solutions based on weld/flange technologies do not.
But what are the environmental implications if liquid cooling becomes more prevalent in datacentres? Even the most efficient air-cooled solutions require a lot of fans, and typically use evaporation to cool the air, resulting in water wastage. Large volumes of warm air are costly and difficult to transport long distances, so data centres need a suitable receptacle – right on their doorsteps – to put it to use. Heated water, at higher temperatures than can be supported with air cooled IT is easier to transport, providing an opportunity for waste heat from data centres to be re-used. This process has the potential to help cut the amount of energy needed to heat nearby homes, offices and industrial or agricultural processes.
Ease of installation and maintenance
Another important consideration is what it will take to deploy and maintain a cooling system. Planning ahead and making provisions for the ability to add liquid distribution does not need to be a complex or a costly task. As previously mentioned, a key to success will be the use of piping solutions that are adaptable, scalable and easy to align. To help address this challenge of expanding rack density - some in excess of over 40KW per rack - Victaulic is working with OCP and a wide variety of liquid solution vendors to deliver high-density liquid cooling solutions in new or operating data centres.
Grooved mechanical pipe joining solutions are available globally and provide a simple, fast and reliable method for adaptable and scalable data centres. As a result, installations and expansions can be made safely, quickly and without interruption while eliminating environmental, health and fire risks associated with other methods, such as welding or brazing. Alignment issues – which can be a huge problem in retrofit pipe solutions – are significantly simplified with advanced technologies in grooved pipe solutions.
The data centre industry is constantly evolving, driven by technology, digital transformation trends and sustainability goals. It's hard to gauge which technologies will emerge as leaders, how the technologies might be standardized or what to expect four or five years from now. However, energy management and sustainability are keys to the future. Industry professionals should be ready to future proof their centres with the latest cooling and energy management solutions.