Microsoft has revealed that it’s been experimenting with a “two-phase immersion cooling technology” to prevent its data centre servers from overheating and causing outages across its cloud-based communications platforms such as Microsoft Teams.

At a Microsoft data centre on the bank of the Columbia River in Washington state, engineers are submerging servers in a steel holding tank filled with boiling liquid.

Unlike water, which is seen as precarious to electronic equipment, the liquid used by Microsoft engineers is harmless to the server hardware as it’s designed to cool its processors by carrying away the heat as it boils.

The liquid has been engineered to boil at 50 degrees Celsius, which is 50 degrees cooler than the boiling point of water. The lower temperature has been specifically chosen in order to carry away the heat while allowing Microsoft’s servers to operate at full power without the risk of failure due to overheating.

According to Microsoft’s data centre advanced development group VP Christian Belady, “air cooling is not enough”. 

“That’s what’s driving us to immersion cooling, where we can directly boil off the surfaces of the chip,” he said.

Husam Alissa, a principal hardware engineer on Microsoft’s team for data centre advanced development, said that the tech giant is “the first cloud provider that is running two-phase immersion cooling in a production environment,” which is the next step in Microsoft’s long-term plan to keep up with the increasing demand for cloud computing.

The demand has been fuelled by the rise of remote working, which depends largely on the reliability of collaboration tools such as Teams or communication tools such as Exchange.

In fact, according to Marcus Fontoura, chief architect of Azure compute, two-phase liquid immersion cooling enables increased flexibility for the efficient management of cloud resources, allowing them to manage sudden spikes in data centre compute demand to the servers in the liquid-cooled tanks. The servers run at elevated power without risk of overheating due to  “overclocking”.

“For instance, we know that with Teams when you get to 1 o’clock or 2 o’clock, there is a huge spike because people are joining meetings at the same time,” Fontoura said. “Immersion cooling gives us more flexibility to deal with these burst-y workloads.”

Using specially-designed liquid to cool the servers is not only cheaper than air cooling but also more sustainable than using water, allowing Microsoft to meet its commitment to replenish more water than it consumes by 2030.