How liquid cooling, RDHx rear doors, and CDUs work together to cool the AI data center.
Liquid cooling uses the superior heat capacity of water or dielectric fluid to absorb and transport heat far more efficiently than air. Apex Thermal systems move heat from the rack to the facility loop with minimal energy input.
Our solutions operate in a secondary loop architecture: a CDU circulates coolant between the heat source (RDHx or cold plate) and a facility heat exchanger, maintaining isolation and precise control.
A Rear Door Heat Exchanger replaces the rear door of a server rack with a liquid-cooled coil. Hot exhaust air from the servers passes through the coil before leaving the rack, transferring most of its heat to the coolant.
The Coolant Distribution Unit is the heart of a secondary liquid cooling loop. It contains redundant pumps, heat exchangers, expansion tanks, filters, and controls to deliver conditioned coolant to racks or cold plates.
Representative capacity and pressure drop values for Apex Thermal products.
| Product | Peak Capacity | Max Flow | Pressure Drop | Form Factor |
|---|---|---|---|---|
| ATR-60 | 60 kW | 15 L/min | < 15 kPa | Rear door |
| ATR-100 | 100 kW+ | 25 L/min | < 20 kPa | Rear door |
| CDU-500 | 500 kW | 75 L/min | Facility dependent | In-rack 42U |
| CDU-1500 | 1.5 MW | 225 L/min | Facility dependent | Row-based |
