About Capture Index prediction models

Capture Index Cooling-Performance Metric

Unlike temperature-based metrics, Capture Index (CI) is solely a function of airflow. There are two kinds of CI:
- Cold Aisle CI: the fraction of air ingested by the rack which originates from local cooling resources (e.g. perforated floor tiles or local coolers)
- Hot Aisle CI: the fraction of air exhausted by a rack which is captured by local extracts (e.g. local coolers or return vents)

CI measures effectiveness of supplying cooling air to rack inlets or scavenging heated air from rack exhausts on a 0% (bad) to 100% (good) scale.
CI is defined in terms of local cooling resources (airflow from tiles, local coolers, local extract vents, etc.) and it measures the robustness and scalability of a grouping of equipment.

Example

Cold Aisle
The Cold Aisle Capture Index of the top-middle rack is 84%. In other words, 84% of the airflow drawn in by that rack originated from the perforated floor tiles. The remaining 16% of inlet air comes from other sources including the room ambient and recirculation from the subject rack and others.

Hot Aisle
The Hot Aisle Capture Index of the bottom-right rack is 66%. In other words, 66% of the exhaust airflow from this rack is captured by the local coolers while the additional 34% escapes, heating the room ambient and, potentially, entering rack inlets.

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