Abandoned cabling
Decommissioning abandoned cabling in data centers improves Power Usage Effectiveness (PUE) by enhancing airflow, reducing cooling requirements, and improving operational efficiency — all of which help reduce total facility power, the numerator in the PUE equation.
Quick Refresher: What Is PUE?
PUE = Total Facility Power / IT Equipment Power
Abandoned cabling contributes to higher facility power use without supporting IT workloads. Removing it directly helps improve PUE by supporting more efficient cooling and airflow management.
What Is Abandoned Cabling?
Abandoned cables are unused or decommissioned data and power cables left in ceilings, under raised floors, or in cable trays. They often accumulate over time during upgrades, migrations, or equipment swaps.
How Decommissioning Abandoned Cabling Improves PUE
1. Improves Airflow Efficiency
Bundles of abandoned cables obstruct airflow under raised floors or in overhead plenum spaces.
These blockages cause hot spots and uneven cooling, forcing CRAC/CRAH units to work harder.
Removing cable obstructions enables smoother airflow, lowering the cooling system’s energy demand.
2. Reduces Cooling Load
Better airflow means cooling units can operate more efficiently and at higher set points.
This allows operators to reduce fan speeds, chiller loads, or even decommission unnecessary CRAC/CRAH units.
Less cooling power = reduced facility power = improved PUE.
3. Lowers Fire Risk and Compliance Overhead
Abandoned cables can be a fire hazard, especially older ones with flammable jacketing (e.g., PVC).
Fire codes (e.g., NFPA 70 / NEC 800) often require removal of unused cables to remain compliant.
Non-compliance may lead to enforced upgrades or shutdowns, disrupting energy optimization efforts.
Proactive cable removal avoids code violations and unplanned downtime.
4. Frees Up Space for Efficient Upgrades
Removing unused cabling opens pathways for modern high-density cabling, fiber, or new containment systems.
These modern systems often require fewer cables with higher bandwidth, lowering energy use per bit.
5. Improves Maintenance Efficiency
Clean cable trays make it easier to trace active connections.
Reduces the chance of accidental unplugging or redundant cabling, which can lead to unnecessary hardware being powered.
Benefit - Impact on PUE
Improved airflow - Reduces cooling power demand
Lower cooling energy - Decreases facility overhead
Reduced fire risk/compliance cost - Avoids energy-wasting emergency retrofits
Easier infrastructure upgrades - Makes space for more efficient systems
Operational clarity - Avoids waste from supporting unknown/idle devices
Final Thought
Decommissioning abandoned cabling is a low-cost, high-impact way to improve data center energy efficiency and PUE. It enhances cooling effectiveness, supports airflow containment strategies, and ensures the facility runs leaner, safer, and more efficiently — all without touching the IT workload.
