Chip to Facility Ramifications of Containment Solution on IT Airflow and Uptime

Abstract

We developed a generalized testing methodology in which IT fans’ internal and external impedance effects are collapsed into a single curve (i.e., flow curve). Such curves can give accurate flow rate predictions of the IT equipment based on RPM logging. Flow curves cover the three possible airflow regions for IT in a contained environment. The experimental procedure is introduced to rank IT equipment based on its air systems, and the flow regions are correlated with the CPU performance. The strength of the IT air system is characterized by the free delivery and the critical pressure points. In addition, the experimentally obtained active flow curves can be used as a numerical boundary condition in various containment designs. Accordingly, for the first time in the literature, the aerodynamic interaction of IT with different air systems in the containment (i.e., BladeCenters, servers, and switches) can numerically be investigated. It is found that stacking IT in a contained environment with no physical consideration can lead to radical reliability problems. The region of reverse flow is discovered to be very possible upon events in the data center. In such a case, the weak IT (e.g., 1U switch) behaves as an open leakage into the sealed containment. On the other hand, at the critical pressure point, minimum forced convection occurs in the weak IT, leading to CPU overheating.