Data center
glossary.
The terms that come up most often in operations, engineering, and diligence work — defined by operators, with the qualifiers that matter.
PUE is the ratio of total facility energy to IT equipment energy — the most-cited efficiency metric in data center operations.
WUE is the ratio of annual water consumption to IT energy consumption — the standard water-side companion to PUE.
N+1 redundancy means a system has one more component than the minimum required to carry the load, so any single component can fail without losing capacity.
2N redundancy means the system has two complete, independent paths — either alone can carry the full load.
ASHRAE TC 9.9 publishes thermal envelope classes A1 through A4 that define recommended and allowable operating temperature and humidity ranges for IT equipment.
The Uptime Institute Tier Classification System rates data center topologies on availability and concurrent maintainability — Tier I through Tier IV.
An RDHX is a chilled-water heat exchanger mounted on the rear door of a server rack that rejects rack heat to a water loop instead of room air.
Liquid cooling moves heat off IT components using a fluid loop instead of air — required for the densest AI and HPC workloads.
DCIM is the software category that unifies asset, capacity, and environmental data for a data center facility.
DCOS is CR Technology's modular platform and operating discipline that unifies operations, engineering, infrastructure, security, DCIM, and metrics into a single pane of glass.