Servers take a bath

A two-phase immersion cooling tank at a Microsoft datacenter. © Gene Twedt, Microsoft.

Remember Microsoft’s underwater data center off the coast of Scotland? Microsoft has tried out all kinds of things to cool its data center servers. Now, Microsoft lifts the veil on another experiment. It is submerging servers in coolant. As you might imagine, they’re not dunking their computers in water, which is electrically conductive, much less in salt water, which is also corrosive to metals. The liquid they use is manufactured by 3M and is composed of perfluorocarbons. Its properties are non-conductivity and an extremely low boiling point of 50° C.

The system operates in a closed loop. The submerged server-racks release heat, which boils the liquid. The evaporation reaches a condenser in the enclosure lid where it returns to its liquid state, then rains down on the racks. This isn’t new technology, but it’s a first for production servers in a cloud. Given Microsoft’s commitment to use less water, this is very efficient. Yet it is not without environmental risks. Perfluorotributylamine, a chemical component of the 3M liquid, has a significant greenhouse effect when it escapes as gas. The container in which the servers soak must be kept tightly shut and closely monitored.

© Gene Twedt, Microsoft.

⇨ The Verge, Tom Warren, “Microsoft is now submerging servers into liquid baths.”

⇨ Microsoft, Innovation Stories, John Roach, “To cool datacenter servers, Microsoft turns to boiling liquid.”

2021-04-06