Rear Door Heat Exchanger (RDHx)

Overview

A rear door heat exchanger replaces or attaches to the rear door of a server rack and uses a liquid-cooled coil to absorb hot exhaust air before it returns to the data hall. Passive models rely on server fans, while active models include integrated fans for higher capacity and airflow control. RDHx is especially useful for operators in Southeast Asia and the Middle East who need to raise rack density while preserving existing white-space layouts, containment systems, and server hardware. It can reduce hot aisle temperature, lower CRAH/CRAC load, and support phased upgrades before or alongside direct-to-chip cooling. Deployment planning should consider rack airflow, door swing, hose routing, condensate risk, water temperature, quick disconnects, and integration with facility monitoring. For sales conversations, RDHx is often an easier entry point because it solves immediate heat rejection issues while leaving future liquid-cooled server adoption open.

Technical Specifications