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Enterprise9 min read

High Density Colocation: What 30+ kW Per Rack Requires

High-density colocation — deployments exceeding 30 kW per rack — presents unique challenges that many data center providers are still adapting to meet. Whether you’re deploying GPU clusters, high-performance computing nodes, or dense storage arrays, understanding the infrastructure requirements is critical.

Power Infrastructure

Electrical Distribution

High-density racks require robust electrical distribution: – Bus duct or overhead power: Traditional under-floor power distribution often can’t support 30+ kW per rack – High-amperage whips: 30A or 60A circuits at 208V or 415V three-phase – Redundancy: 2N power at high densities requires significant infrastructure investment

UPS and Generator Capacity

Verify that the facility’s UPS and generator systems can support your density requirements with full redundancy. Some facilities have adequate raised-floor power but insufficient backup capacity for high-density zones.

Cooling Architecture

Air Cooling Limitations

Traditional raised-floor air cooling tops out around 15–20 kW per rack. Beyond that, supplemental or alternative cooling is essential: – In-row cooling units: Placed between racks to provide targeted cooling – Hot/cold aisle containment: Maximizes cooling efficiency but has density limits – Chimney cabinets: Direct hot air exhaust above the rack

Liquid Cooling Solutions

For 30+ kW, liquid cooling becomes increasingly necessary: – Rear-door heat exchangers (RDHx): Remove 50–100% of rack heat load with chilled water – Direct-to-chip: Liquid cooling plates on CPUs/GPUs with facility water supply – Immersion cooling: Single-phase or two-phase immersion for the densest deployments

Facility Readiness Assessment

Before committing to a facility, conduct a thorough assessment: 1. Current infrastructure capacity: Can the facility deliver your required density today? 2. Expansion capability: Is there room to grow density as your needs increase? 3. Cooling infrastructure: What cooling options are available or planned? 4. Structural considerations: Can the floor support the weight of high-density racks?

At Stacked AI, we evaluate facility readiness for high-density deployments as part of our sourcing process, ensuring you select a provider that can support your requirements now and in the future.