Chinese researchers have allegedly developed a new technique that can supercool liquid cooling medium to sub-zero levels in less than 30 seconds. This new process, the researchers explain, could offer interesting options for keeping energy-hungry data centres cool. 

According to the South China Morning Post (SCMP), this new process is not a new refrigerant or magic coolant. It is, in fact, a novel pressure-driven chemical cooling process that exploits how salts behave in water. 

The key ingredients of the new process revolve around something called ammonium thiocyanate (a salt with unusual solubility behaviour), water, and, of course, pressure. 

You can liken the process to something like a wet sponge, where, when under pressure, a lot of ammonium thiocyanate can dissolve into water. This creates a highly concentrated (ie, saturated) salty solution.

Cooling AI with salt

When pressure is suddenly released, the salt wants to re-dissolve or reorganise into a more stable state. That re-dissolving process absorbs a huge amount of heat from its surroundings.

This results in temperatures plummeting very fast, in fact, tens of degrees in just a matter of seconds. This is classic endothermic dissolution (a process that pulls heat in), but supercharged by pressure control. 

This differs from traditional cooling in data centres that tend to rely on things like fans, air conditioning, chilled water loops, or immersion liquid cooling. While effective, these solutions require continuous energy input to move heat somewhere else. 

This new process, on the other hand, uses stored chemical potential (the pressurised salt solution). It can release cooling almost instantly and delivers very high cooling power for short bursts. 

For situations like artificial intelligence (AI) data centres, this could prove to be a game changer. Such data centres tend to require large amounts of graphical processing units (GPUs) and other power-hungry hardware that generate a lot of heat when running.

For this reason, they tend to dump a huge amount of heat into very small spaces continuously. They can also suffer from sudden thermal spikes when AIs are tasked with computationally intensive processes like training.

This can lead to unpredictable heat surges that already complicate a tricky heat management situation. It is for this reason that cooling is often one of the biggest overheads for data centres. 

Not out of the woods yet

In some cases, cooling can constitute between 30% and 50% of a data centre’s total power. This new rapid salt cooling process could help by providing a useful tool to handle thermal shock rapidly.

It could, for example, handle short, intense heat bursts without spinning up huge cooling systems. This process could also help reduce peak cooling loads, which is where costs tend to explode.

In this sense, it can be thought of as less of a replacement for things like air conditioning, but rather a cooling buffer or kind of capacitor. But while promising, it is important to note that the technology is not a 'silver bullet'.

For example, the salt solution needs to be repressurised once 'spent'. This will introduce energy costs that cannot be ignored.

Since the solution requires salt, there are likely significant corrosion and stability questions to be answered before using it in the real world. It is also not clear if the technology could be scaled enough to make it economically viable.