How to Improve Data Center PUE

To improve Power Usage Effectiveness, operators can decommission or consolidate a range of non-IT infrastructure and underutilized assets that consume energy without supporting compute. Here’s what to scrutinize.

Power infrastructure

• Redundant or legacy UPS systems. Old, oversized, or redundant units run at low efficiency. Consolidating or upgrading to modular, right-sized UPS reduces losses and cooling load.
• Transformers and PDUs. Remove or consolidate unused units, especially those with low utilization or poor conversion efficiency.
• Inactive power circuits. Abandoned circuits still energize wiring and create phantom loads; decommissioning them reduces baseline draw.

Cooling infrastructure

• Underutilized CRAC/CRAH units. Retire cooling in areas where IT load has decreased or migrated.
• Inefficient legacy systems. Replace old chillers, compressors, or DX units with economizers, liquid cooling, or variable-speed fans.
• Overcooled zones. Decommission fans or chillers serving low-density racks and adopt hot/cold-aisle containment.

IT and network infrastructure

• Idle "zombie" servers that draw power without doing work.
• Legacy switches and storage that consume more power per unit of data; consolidate onto efficient hardware.

Physical and facility infrastructure

• Unused racks and cabinets that disrupt airflow.
• Outdated lighting, upgrade to occupancy-sensor LED.

Environmental and support systems

• Oversized humidifiers/dehumidifiers that are no longer needed.
• Battery-room HVAC that can be removed once battery systems are decommissioned.

Improving PUE is about aligning infrastructure with actual IT load. Anything not directly contributing to compute, storage, or networking should be questioned. Strategic decommissioning, combined with right-sizing and modernization, yields substantial gains.