SemiAnalysis/nVent cited RDHx capacity range; no universal rack-kW cliff
30–40 kW typical RDHx; >50 kW with active fans; not a universal limitobserved
| Value kind | observed — Reported measurements, counts, and specifications keep the precision and scope stated by their source; an exact specification is not treated as a range. |
|---|---|
| Scope | Select on the named door/rack, air and water conditions, fan state, containment, heat-capture target, residual room heat, climate/rejection, serviceability, redundancy, and future density. |
| Caveat | Reference capacity, not a universal ceiling; verify named door/rack, water and air conditions, fan state, containment, and capture target. |
| As of | 2025-02-13 |
| Source | SemiAnalysis, Datacenter Anatomy Part 2 – Cooling Systems, 13 February 2025; RDHx discussion citing nVent · RDHx section: 30–40 kW typical, increasing above 50 kW with rear-door fans ('Active RDHx') |
| Review | checking…review by 2026-12-22 · standard cadence |
| Recorded changes | last 2026-08-24 · 14 revisions tracked |
| Claim id | practical-air-cooling-ceiling-per-rack-rdhx-50 |
Where the guide uses it
- 0.1 Orientation: The AI Data Center as a Single Co-Designed Machine
- 0.2 How to Read This Guide: Decisions, Consequences & Reference Data
- 1.1 The Archetype Decision Framework: Workload Is the Master Variable
- 1.2 Training Data Centers: Synchronous, Dense, Checkpointable
- 1.7 The Requirements-and-Consequences Matrix
- 5.1 Thermal Fundamentals & the Density Wall
- 5.2 Air Cooling at the Limit
- 5.3 Rear-Door Heat Exchangers & Air-Assisted Liquid Cooling (The Bridge)
- 6.1 Building Typologies & Data-Hall Layout
- A Standards & Specifications Cross-Reference Matrix
- C Decision Tables & Calculators
← Full numbers register — every date-stamped figure in the guide, with revision history.