IBM 81Y2911 40mm Fan Module for Flex System Enterprise Chassis

This is a compact, high-performance 40mm dual-rotor fan module that provides forced-air cooling to the chassis components, including compute nodes (e.g., x220, x240, x440), I/O modules, and the Chassis Management Module (CMM).

• The Flex System Enterprise Chassis uses multiple 40mm fan modules (typically 8–10 active fans in the chassis) arranged in rows for front-to-back airflow, ensuring optimal thermal management for high-density blade/compute node deployments.
• Each fan is PWM-controlled (variable speed based on temperature/load from the CMM), with integrated tachometer feedback for RPM monitoring, fault detection, and alerting via the CMM firmware.
• The module is hot-swappable (when redundant fans are present), with no tools required for replacement, minimizing downtime in production environments.