SemiAnalysis RDHx capacity range
30–40 kW typical RDHx; >50 kW with active fansestimate
| Value kind | estimate — Interpret this value according to its displayed kind, scope, source, and as-of date. |
|---|---|
| Scope | Choose a door on its rated water and air temperatures, fan state, containment, heat-capture target and the room heat it leaves behind, plus climate and heat rejection, serviceability, redundancy and future density. |
| Caveat | Reference capacity, not a universal ceiling: a door's rating depends on the rack's airflow, the water and air temperatures it was rated at, fan state and containment. |
| As of | 2025-02-13 |
| Source | SemiAnalysis, Datacenter Anatomy Part 2 – Cooling Systems, 13 February 2025 (RDHx section) · 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 2026-10-19 · 15 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
- 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)
- C Decision Tables & Calculators
← Full numbers register — every date-stamped figure in the guide, with revision history.