Vertiv 8403E-29-X 29kW Precision Cooling Unit with Liebert iCOM Control
Overview
The Vertiv 8403E-29-X is a precision cooling unit built for data center rows and computer room environments where tightly managed thermal loads are non-negotiable. Rated at 29kW net sensible capacity (91.4 kBtuh), this unit handles real heat loads from densely packed server infrastructure — not the inflated total capacity numbers that include latent heat you don't have in a data center. The 8403E-29-X (often searched as 8403E 29 X) supports both upflow and downflow airflow configurations, giving your facilities team the flexibility to adapt to raised-floor or overhead-plenum room designs without swapping units.
Key Features
- 29kW Net Sensible Capacity (91.4 kBtuh): Sensible capacity is what actually removes heat from your IT equipment — the 8403E-29-X's 26.8kW [91.4 kBtuh] net sensible rating is the number your thermal model should be built around, not the 31kW [105.9 kBtuh] total figure that bundles in latent dehumidification load. For a rack-dense row, that difference in planning accuracy means avoiding undersized cooling that trips thermal alarms at 80% load.
- Variable-Speed EC Fan Technology: EC (electronically commutated) fans modulate speed in response to actual cooling demand rather than running flat-out at fixed speed. In practice, this cuts fan energy draw significantly during partial-load conditions — which is most of the time in real deployments. Paired with the iCOM controller, the unit adjusts airflow dynamically to track load shifts across the room.
- 4,300 CFM Nominal Airflow: At 4,300 CFM, the unit moves enough air to serve a meaningful row segment without creating pressure differentials that destabilize adjacent cooling zones. Proper airflow modeling for your room layout will determine how many units you need and where — this CFM rating is the input for that calculation.
- Upflow and Downflow Airflow Direction: Dual airflow direction support means the same unit can be configured for raised-floor environments (downflow into the floor plenum) or overhead-return rooms (upflow into a ceiling plenum). This is a real operational advantage when retrofitting an existing room or standardizing on a single SKU across mixed-design facilities.
- R-410A Refrigerant Circuit: The 8403E-29-X runs on R-410A, a widely available refrigerant that supports efficient heat rejection through the condenser circuit. Factor in the current regulatory trajectory for refrigerants when planning long lifecycle deployments — confirm your facility's compliance posture with local environmental regulations.
- Liebert iCOM Unit Control: iCOM is Vertiv's purpose-built precision cooling controller. It handles unit-level monitoring, setpoint management, and supports coordination with other iCOM-equipped units in a row or room configuration. For facilities teams managing multiple cooling units, iCOM's inter-unit communication capability is the foundation for room-level thermal management without requiring a separate BMS integration for basic load balancing.
- 98.9 kBtuh (29kW) Total Nominal Capacity: The headline total capacity includes both sensible and latent cooling. In most data center environments, nearly all of the load is sensible (servers generate dry heat), so the sensible capacity figure of 91.4 kBtuh is what determines actual IT cooling coverage in your deployment scenario.
Integration and Compatibility
The Liebert iCOM control system on the 8403E-29-X is designed to integrate with Vertiv's broader thermal management ecosystem. Multiple iCOM-controlled units can be configured to operate in coordinated mode, distributing load across a row and providing redundancy if one unit goes into fault. For BMS integration, iCOM typically supports Modbus and BACnet protocols — verify your specific interface requirements against the unit's communication module configuration before commissioning. The unit's 84-inch height and 29-to-32-inch width range fits standard data center row footprints, but confirm ceiling clearance for top-of-unit service access and plenum depth for airflow before finalizing placement.
Frequently Asked Questions
Q: What is the net sensible cooling capacity of the Vertiv 8403E-29-X?
A: The 8403E-29-X delivers 91.4 kBtuh (26.8 kW) net sensible capacity. This is the figure that directly offsets heat generated by IT equipment — the total nominal capacity of 98.9 kBtuh (29 kW) includes latent load that is typically minimal in data center environments.
Q: Does the 8403E-29-X support both upflow and downflow configurations?
A: Yes. The unit supports both upflow and downflow airflow directions, making it compatible with raised-floor environments (downflow into the floor plenum) as well as overhead-return room designs (upflow into ceiling plenums).
Q: What refrigerant does the 8403E-29-X use?
A: The 8403E-29-X uses R-410A refrigerant for its heat rejection circuit. Verify your facility's refrigerant compliance requirements and local environmental regulations before installation and service planning.
Q: What control system does the 8403E-29-X use, and can it coordinate with other units?
A: The unit ships with Liebert iCOM unit control. iCOM supports inter-unit communication, enabling coordinated operation across multiple units in a row or room for load balancing and basic redundancy without requiring a separate building management system for thermal coordination.
Q: What is the airflow rating for the 8403E-29-X?
A: Nominal airflow is 4,300 CFM. This figure is the baseline for airflow modeling when planning row segment coverage and pressure balance in your cooling layout.
Q: What width range does the 8403E-29-X accommodate?
A: The unit is designed for a 29-to-32-inch width range at 84 inches in height, fitting standard data center row footprint constraints in that size class.
The spec I keep coming back to on the 8403E-29-X is the 91.4 kBtuh net sensible capacity — 26.8 kW of actual IT-load cooling. When we size precision cooling for a row deployment, the sensible number is the only one that matters, and Vertiv publishes it clearly here. That said, this is a unit you need to model properly before ordering: the 4,300 CFM airflow rating and the upflow/downflow configuration choice both have to be resolved against your room's actual floor or ceiling plenum depth before you commit to placement.
Technical Highlights:
- Variable-Speed EC Fans: Fan energy is a meaningful fraction of total CRAC/CRAH operating cost. EC fans modulating speed to actual demand rather than running fixed-speed is the most impactful efficiency feature on this unit — the savings are real during partial-load hours, which is most of operational life.
- Liebert iCOM Control: iCOM's inter-unit coordination is worth specifying correctly from the start. If you're deploying multiple units in a row, configure coordinated mode during commissioning rather than running units as isolated standalones — the load distribution and fault response are meaningfully better.
- Dual Airflow Direction (Upflow/Downflow): A single SKU that covers both raised-floor and overhead-return rooms simplifies procurement and spare-parts management across mixed-design facilities. Verify the plenum depth on your specific room layout before finalizing airflow direction — insufficient plenum depth is the most common installation mistake on units in this class.
Deployment Considerations:
- The 29-to-32-inch width range means the unit fits standard row footprints, but measure your aisle cabinet spacing before ordering — tight tolerances between cabinets can complicate service access on the sides of the unit.
- R-410A is the refrigerant circuit; while widely serviceable today, factor in your facility's long-term refrigerant strategy and local regulatory environment when planning for units expected to run 10+ years.
The 8403E-29-X is a well-matched choice for mid-density computer room rows where you need reliable 29kW sensible capacity with room-level coordination capability — particularly in facilities running mixed upflow/downflow room designs where standardizing on a single configurable unit reduces spare inventory complexity.
