Last updated: 5 October 2026
Room-level coolant distribution units, 900 to 2000 kW
A coolant distribution unit (CDU) exchanges heat between the server liquid cooling loop and facility water. A room-level CDU does this from the plant room and feeds a ring network serving many rows. ToneCooling's TC-CDU-RL series covers 900, 1200 and 2000 kW for Australian data centres.
Room-level or in-row coolant distribution unit?
Both do the same job: they exchange heat between the server loop and facility water. The difference is where they sit and how far the secondary loop has to run.
| Room-level CDU (this page) | In-row CDU | |
|---|---|---|
| Location | Plant room, outside the data hall | In the rack row, beside the cabinets |
| Secondary distribution | Ring network serving many rows | Short runs to the racks in its row |
| Facility water in the data hall | No | Yes, to every CDU |
| Best fit | Large halls and phased fit-outs on one ring | Row-by-row deployment and retrofits |
What are the TC-CDU-RL room-level CDU specifications?
| Model | TC-CDU-RL900 | TC-CDU-RL1200 | TC-CDU-RL2000 |
|---|---|---|---|
| Rated heat exchange | 900 kW | 1200 kW | 2000 kW |
| Rated flow | 1330 L/min | 1720 L/min | 3000 L/min |
| Pumps | Dual pump | ||
| Primary supply / return | 35 / 45 °C | ||
| Primary fluid | Softened water, PG25 or EG25 | ||
| Secondary supply / return | 40 / 50 °C | ||
| Secondary fluid | Softened water, PG25 or EG25 | ||
| Dimensions W × D × H | 950×1500×2200 mm | 1200×1800×2200 mm | 1200×2000×2200 mm |
| Power | 2 circuits, 3-phase AC380–415 V, 50 Hz | ||
| Dual power input (optional) | Mains / UPS / diesel generator | ||
Rated with pure water. For glycol mixtures or other capacities, the selection is confirmed by our engineers.
What does a room-level CDU include?
- Redundant key components, self-holding pumps and valves, non-stop dual power switching
- Multi-mode control: differential pressure, flow, cold or hot standby, group and remote control
- Automatic networking of multiple units for group management
- Stepless regulation of cooling capacity and differential pressure
- High lift and large flow for large ring networks
- Online automatic liquid replenishment, sanitary-grade pipework, high-precision filtration, leak detection and anti-condensation
- RS485 and RJ45; Modbus, TCP and UDP protocols
Australian project notes
Supply: the 380–415 V three-phase input covers Australian 400 V supply. The electrical safety compliance pathway for Australia and New Zealand is confirmed per project at quotation.
Ring network: pair the CDU with a prefabricated ring pipeline and rack manifolds. See loop assemblies.
Heat rejection: the 35 °C primary supply suits dry cooling units for much of the year in southern climates. Hot inland sites may need closed-circuit towers.
Room-level CDU questions
How many racks can one RL2000 serve?
At 2000 kW it can serve around 15 racks at 130 kW each, or more at lower densities. The real limit is usually the ring pipeline's flow and pressure drop, so we check both together.
How is redundancy handled?
Each unit has dual pumps and dual power with non-stop switching. For N+1 at plant level, several units can be networked for group control on the same ring.
Where is the CDU supplied from?
ToneCooling supplies the TC-CDU-RL series from China. ToneCooling Australia handles selection, AUD quotes, documentation, customs and after-sales.
What cooling system does a liquid-cooled data centre need?
Typically cold plates on the chips, a coolant distribution unit to run the server loop, and heat rejection such as dry coolers or cooling towers on the facility side. Room-level CDUs suit large halls on one ring network.
Send your hall load
Send the total IT load on liquid, the number of racks and the facility water temperatures. We'll size the RL units and the ring.
- Liquid-cooled IT load (kW)
- Rack count and layout
- Facility water temperatures
- Redundancy target
Sources and standards referenced: ASHRAE TC 9.9 (data centre thermal guidelines); Open Compute Project cooling environments; Standards Australia (AS/NZS standards). Specifications on this page come from ToneCooling datasheets; project values are confirmed at quotation.