A big conundrum for today’s global industry is how to optimise cooling technology as rack density in data centres grows, placing ever-increasing demands on power. This is about finding the right time to move to different methods to optimise costs and efficiency.

“Data centre operators need cooling solutions designed to be safe, stable and efficient that are compatible with sensitive infrastructure,” says Fabian Ipfelkofer, EMEA business development manager for data centre applications at global specialist materials firm Solstice Advanced Materials. “They also need to adapt to evolving environmental regulations.”

This is not a straightforward challenge, especially when industry players are catering for data centre types from mega-scale and AI-inferencing to compact edge facilities in widely varying locations.

Ipfelkofer says this is where data centre players can benefit from working with those that have direct expertise in liquid science and chemistry.

Talking to the experts

One of these is Solstice Advanced Materials, a global specialty materials company. The company develops high-performance solutions that enable critical industries and applications.

Supported by a portfolio of technologies, Solstice serves more than 3,000 customers in over 120 countries and territories, with over 130 years of experience in advanced materials.

Ipfelkofer explains that Solstice provides refrigerants for legacy air cooling and phase-change fluids for liquid cooling to cooling equipment manufacturers, which then sell to the data centre industry.

As the firm is brand-independent and provides options across the board, it is increasingly consulting with data centre and cloud operators, hyperscalers, AI players and enterprises to help them choose the best options for their needs.

Solstice’s expertise expands to global industrial and regulatory experience in refrigerants and fluids, enabling it to advise on optimising for different markets while meeting sustainability goals.

“This is where Solstice’s expertise becomes relevant,” says Ipfelkofer. “Our strength lies in advanced fluid chemistry and low-global-warming-potential refrigerant innovation.”

This expertise is also important given that he thinks the days of ‘one-size-fits-all’ are over, with the industry moving towards a mix of options for different needs.

Fluid approach

That said, Ipfelkofer sees the industry moving increasingly towards liquid cooling as the more efficient option than air due to its higher thermal conductivity – and, ultimately, specifically towards two-phase liquid cooling. This is because the two-phase option provides stronger heat-transfer efficiency than single-phase cooling by boiling the fluid into a vapour before it condenses again, rather than staying in the liquid form.

“While there is no one-size-fits-all solution, liquid cooling, particularly two-phase systems, is emerging as a promising option for high-density AI workloads in certain scenarios, depending on system requirements,” says Ipfelkofer.

The choice of when to move into two-phase cooling is partly dependent on rack densities in data centres over time.

Ipfelkofer explains that many facilities are moving from racks at the 10 to 20kW level to those from 50 to 100kW. Once they start moving to the upper part of that 100kW level and beyond, he says two-phase cooling becomes more attractive. Ipfelkofer believes this will start happening at scale over the next three years.

Getting ahead

Two-phase cooling is more expensive and complex than the single-phase option. But Ipfelkofer believes there are big advantages to starting on that track now, one of which is data centre players getting ahead of the game for the future.

It also saves energy because less is needed to shift vapour through pipes than water. Two-phase cooling also uses no water, harnessing a heat-transfer fluid that is safe to IT equipment. That means it has both strong sustainability and safety credentials, being particularly useful for regions with power and water constraints.

“Two-phase cooling is an area of growing interest,” says Ipfelkofer. “Our role is to help players evaluate options.”

For now, he says, data centre players need to consider their mix of options wisely, while understanding where the market is going in the future. “Cooling approaches are set to play an increasingly strategic role, evolving to support greater efficiency and more sustainable power use.”