Most large data centers now operate using chilled water cooling, with chillers supplying water to data center cooling units, usually, computer room air handlers, that take heat from the servers and return it to the chillers where the heat is rejected to air and the process starts again. Much of the improvement focus over the past decade has been on the equipment itself, but the chilled water system as a whole is now under the spotlight.

There are two main types of architecture: “variable primary” and “fixed primary, variable secondary” deployed, with the US favoring the former and Europe the latter. But a shift is occurring and it has major implications for how data centers in Europe are managed and optimized….