Vertiv Liebert XDU Coolant Distribution Unit

Manufacturer: Vertiv

Liebert XDU spans a 70 kW liquid-to-air unit to the 1368 kW XDU1350, and Vertiv now positions CoolChip CDU as its successor.

This model is part of SecondWatt’s liquid cooling research catalogue. Specifications and price observations are included where supported by sources. Equipment availability and commercial terms require confirmation.

Vertiv Liebert XDU coolant distribution unit dossier: published specifications, deployment context, lifecycle notes and inspection guidance.

Why it matters

The XDU1350 is rated 1368 kW at a 4 deg C approach temperature difference and 2912 kW at 8 deg C in a 900 mm wide cabinet, so one unit can carry a full AI row. Secondary filtration is 50 micron triple redundant to permit on-line cleaning, and the unit runs dual pumps in N+1 or triple pumps in N, so redundancy is a build option rather than a second cabinet. Vertiv publishes the application and planning guide and the operation and maintenance manual for the XDU1350 as open PDFs, so piping, filtration, coolant and electrical service can be checked against the design before a quote is requested.

Who buys it

Hyperscale and colocation operators, AI cloud builders, EPCs and national laboratories deploying direct-to-chip racks that perimeter air handling can no longer serve. The liquid-to-air XDU070 and the 60 kW liquid-to-air unit sell into retrofit halls with no facility water at the row, rejecting instead into room air. The liquid-to-liquid XDU450, XDU600 and XDU1350 sell into purpose-built AI halls where a chilled or process water loop already reaches the row and the question is how much secondary load one cabinet can carry.

Role in the data center

Thermal (not electrical) infrastructure: the CDU is the hydraulic interface between the facility water system (primary/chilled or condenser water loop) and the technology cooling system (secondary loop) feeding direct-to-chip cold plates, rack manifolds, rear-door heat exchangers and in-row coolers. It isolates the two loops via a heat exchanger and regulates secondary flow, pressure, temperature and fluid quality for high-density AI/HPC racks. The liquid-to-air variants (XDU060/070) reject heat into the room instead, allowing liquid-cooled servers to be deployed in existing air-cooled halls served by perimeter CRAH/CRAC units. Electrically it is a load downstream of the mechanical/UPS-backed distribution board, not part of the critical power chain itself.

Key specifications

Technical summary

XDU1350 (liquid-to-liquid): 1368 kW heat transfer at 7.2 F (4 C) approach temperature difference with 89.6 F (32 C) ASHRAE W3 facility water; secondary circuit 320 gpm (1200 l/m) at 35.4 psi (2.44 bar) external differential pressure; three pumps with three inverters for redundancy, RS485-controlled for seamless changeover and dual/triple pump modes; triple-pump mode per guide specification gives up to 1800 l/min (475 GPM) at 2.0 bar (29 psi) external pressure drop, twin-pump run/standby 1200 l/min (317 GPM) at 2.5 bar (36 psi); 4 in. low-pressure-drop pipework; dual heat exchanger; triple redundant 50 micron secondary filters. XDU450 (liquid-to-liquid): 450 kW at 7.2 F (4 C) approach; secondary flow 132 gpm (500 l/m) at 36 psi (2.5 bar) external DP; dual pumps and dual inverters; 2.5 in. pipework; all-stainless secondary circuit with self-filling and venting; dual redundant 50 micron secondary filters plus 500 micron primary filter. Liebert XDU 60 kW liquid-to-air variant: 2000 x 600 x 1175 mm (78.75 x 23.625 x 46.25 in.) H x W x D; dry weight 361 kg (796 lb), wet 384 kg; 208 V, 3-phase, 60 Hz supply, 15 A full-load current; 3.0 kW maximum input power at 100% fan speed, 1.3 kW nominal at 50%; 32.1 kW nominal / 52.2 kW maximum cooling at 45 C water delivery and 24 C air inlet; fluid flow 46.2-75.3 l/min (12.2-19.9 USGPM); airflow 2825-5650 m3/h (1663-3325 CFM). XDU070 footprint cited by Vertiv as 4.59 ft x 3.94 ft x 7.22 ft (L x D x H). Performance is published against ASHRAE W1-W4 facility water classes (42.8 F/6 C through 113 F/45 C primary).

Major variations

Liebert XDU family (branded Vertiv Liebert XDU, now superseded by the Vertiv CoolChip CDU line): XDU060 / XDU070 liquid-to-air row-based CDU (no facility water required); XDU100 in-rack liquid-to-liquid CDU; XDU450 row-based liquid-to-liquid CDU; XDU600 liquid-to-liquid CDU; XDU1350 liquid-to-liquid CDU (including revised XDU1350B hardware per Vertiv document set SL-71308/SL-71309/SL-71310). Vertiv positions the Vertiv CoolChip CDU as the next-generation replacement family spanning 70 kW liquid-to-air and 100 / 450 / 600 / 1350 / 2300 kW liquid-to-liquid ratings.

Configurations and options

The variant decision sets most of the price. XDU070 and the 60 kW unit are liquid-to-air and need no facility water; XDU450, XDU600 and XDU1350 are liquid-to-liquid and need a primary loop at the row. Pump build is ordered, not field-added: the XDU450 ships single pump N, dual pump N+N or a dual-pump run mode, and the XDU1350 ships dual pump N+1 or triple pump N, drawing 13.7 kW at two pumps and 20.5 kW at three. Electrical build is fixed at order and region-specific, the XDU450 alone offering 400 V 50/60 Hz, 480 V 60 Hz, 208 V 60 Hz and 200 V 50/60 Hz for Japan. Secondary 50 micron filtration is an as-fitted option, and where it is absent the planning guide requires 500 micron filtration in the field piping instead. Primary and secondary connections exit top or bottom. On the XDU070 a seventh fan is available above the six-fan N+1 arrangement.

Compatibility and dependencies

The XDU1350 sits between a facility water loop and a direct-to-chip secondary loop. Both circuits terminate in 4 inch DN100 sanitary flanges with 316 stainless fittings and EPDM seals, top or bottom exit. Primary water must be filtered to 500 microns or 35 mesh minimum upstream; the secondary carries 50 micron triple-redundant elements cleanable on line. Primary coolant is water or water/glycol, secondary is water, water/glycol or another compatible sensible-phase liquid, and the planning guide states automotive antifreeze must not be used. Supply is held between 10 and 52 deg C with dew-point control standard, which keeps the secondary above room dew point at the cold plates. Vertiv recommends a monitored fluid-detection system wired to close field-installed shut-off valves. Monitoring is RS485 Modbus RTU, TCP/IP SNMP, CLI and a webserver.

Pricing and availability

Published price range: Vertiv and its authorized resellers publish no list price for XDU-class CDUs; pricing is configuration- and project-dependent (capacity, pump count, filtration, controls, commissioning scope) and is issued by quotation.. No published price series exists for this SKU family, so trend commentary is directional and market-level only. Demand-side pressure has been strongly upward: Dell Oro Group reported the data center direct liquid cooling market grew 156 percent year over year in 2Q 2025 and projects the liquid cooling market to approach roughly 7 billion USD in manufacturer revenue by 2029, with thermal management forecast at about a 20 percent CAGR. That demand surge, combined with constrained lead times for pumps, heat exchangers and stainless fabrication, has generally supported firm-to-rising transaction pricing and extended lead times since 2021. Offsetting downward pressure comes from rapid supplier entry into the CDU segment, which Dell Oro characterizes as an increasingly crowded, competitive category, plus scale effects as CDUs standardize around hyperscale reference designs. Net expectation: flat to modestly higher nominal pricing per unit with declining USD per kW of cooling capacity as unit capacities scale from 450 kW to 1350 kW and 2300 kW.

Lifecycle and maintenance

Vertiv does not publish an MTBF figure for the XDU family in public literature. Design intent is concurrent maintainability: redundant pumps/inverters and redundant replaceable filter cartridges (dual 50 micron on XDU450, triple 50 micron on XDU1350, plus a 500 micron primary filter on XDU450) allow filter and pump service without shutting the secondary loop down. Public operation and maintenance manuals exist (XDU1350 O&M SL-70619 and SL-71310; XDU070 installation/commissioning SL-71110 and application/planning SL-71111), and installation and planning guides are downloadable, and specific service intervals, fluid change intervals and design life are stated in those manuals rather than on the marketing pages. Expected service life for this class of mechanical plant is typically aligned with data center mechanical equipment cycles (10-15 years) but Vertiv does not publish a figure. Note the family is in transition to the Vertiv CoolChip CDU line, which has end-of-life/spares planning implications for new XDU purchases.

Common failure points

• Primary strainer and 500 micron filter with bypass — Once the bypass opens on a loaded element, unfiltered facility water reaches the brazed plate exchanger and approach temperature drifts up at constant flow
• Secondary 50 micron filter set — Rising secondary differential pressure and falling flow to the cold plates before any alarm on capacity
• Glycol inhibitor package in the secondary loop — Inhibitor depletion and pH falling out of the 7.5 to 9.0 band, attacking copper, brass, solder and aluminum wetted surfaces
• Dew-point control and secondary setpoint — Condensation on secondary piping and cold plates when the supply setpoint is driven below room dew point within the 10 to 52 deg C band
• 4 inch DN100 sanitary flange gaskets — Weeping at the primary or secondary termination where EPDM gaskets have taken a compression set after a disconnection
• Leak detection interlock to field shut-off valves — Leak detection annunciates but does not isolate, because the field-installed supply and return valves were never wired to it
• Variable-speed pump set — One pump degraded in a dual N+1 or triple N arrangement, so rated flow is only reached with the redundant pump running

Inspection checklist

Read the nameplate for the variant and the electrical build first; XDU070, XDU450, XDU600 and XDU1350 share a family name and little else. Confirm whether secondary 50 micron filtration is fitted, because where it is not the field piping must carry 500 micron filtration. Pull the primary and secondary elements and log differential pressure across each. Draw a coolant sample and have glycol concentration, pH and inhibitor level measured before accepting the fluid in place. Inspect the 4 inch flange faces and EPDM gaskets for tracking or compression set. Run each pump alone and record flow and head against 1200 l/m at 2.44 bar on two pumps and 1800 l/m at 1.98 bar on three. Prove dew-point control operates and that leak detection drives the field shut-off valves. Confirm the overcurrent device matches the pump count ordered.

Procurement channels

Vertiv sells the XDU family direct and through its authorised channel, and partner catalog pages present the units as quote-only rather than priced. Vertiv positions the CoolChip CDU line at 70 to 2300 kW as the next generation of the Liebert XDU family, and the XDU product pages route readers to it, so current orderability, lead time and spares support for a specific XDU model number should be confirmed in writing before a purchase order is raised.

Regional notes

Electrical build is fixed at order and differs by market. The XDU450 datasheet lists 400 V 50/60 Hz three phase for EMEA, 480 V 60 Hz and 208 V 60 Hz three phase for North America, and 200 V 50/60 Hz three phase for Japan. The XDU1350 is 400 V 50/60 Hz in the EMEA datasheet and 480 V 60 Hz in the North America datasheet, fused at 63 A in two-pump mode and 80 A in three-pump N mode. The XDU070 is single phase, 115 V 60 Hz at 16 A or 230 V 50 Hz at 8 A. The XDU450 datasheet carries CE, cULus and RoHS; the XDU070 brochure lists CE, cULus pending and RoHS. UL certifies CDUs containing no refrigerant to UL/CAN/IEC 62368-1, applied identically in North America and internationally.