A closed cooling loop is a facility cooling design that recirculates the same water or coolant through pipes, pumps, heat exchangers, and chillers instead of continuously consuming fresh water through open evaporation. Because the fluid stays contained, the system can reduce water loss, lower contamination risk, and make operating costs more predictable, depending on the site design.
In cyber security, cooling loops matter because data centers are part of the critical infrastructure that keeps digital services running. Attackers may not target the loop directly, but they can disrupt the building management system, sensors, valves, or pump controls that regulate it. Defenders monitor these systems for unauthorized changes, loss of telemetry, and abnormal temperatures. A closed loop can improve resilience, but only if its controls and monitoring are secured.