Free Cooling

Free cooling is a data center cooling method that takes advantage of local climate or geologic features to reduce reliance on mechanical refrigeration. Some data centers located in cool climates circulate ambient cool air to cool equipment, saving energy and water by eliminating the process of conditioning the air. Other data centers located near naturally cold water features use this water for liquid cooling, saving energy by eliminating the process of chilling the water.

For example, in Marseille, France, Interxion sources water from a tunnel that carries flowing water at a natural, consistent temperature of 15C. Although the water still requires some filtration, the facilities bypass the need for extensive cooling processes, improving its power usage effectiveness to 1.11 compared to the average PUE of 1.38 for liquid cooling.