Location Considerations; Air-Distribution Considerations For Downflow Units - Vertiv Liebert CW Series Installer And User Manual

Table 3.1 Dimension Planning Drawings (continued)
Document Number
Plenumsfor UnitswithECFans
DPN004604
DPN004605
DPN003214
DPN003213
Plenumsfor UnitswithForward-curvedBlowers
DPN003204
DPN003205

2.2 Location Considerations

For a downflow unit, the unit can sit on an accessible, elevated flooring system. It may be necessary to furnish additional
pedestal support below the unit to ensure maximum structural support. A separate floor stand for the unit may be used as
support, independent of the elevated floor and installed prior to the flooring system.
For downflow and upflow units, provide approximately 34 in. (864 mm) service clearance on the left, right and in front of the
unit whenever possible. The minimum space required for service is 18 in. (457 mm) on the left end, 18 in. (457 mm) on the
right end and 24 in. (610 mm) in front of the unit. This space is necessary to permit routine maintenance, such as replacing
filters and adjusting the fan speed. On downflow and upflow CW106 and CW114 models, left- and right-end minimum
clearances are 0 in. (0 mm) except for rear return.
Avoid installing units in an alcove or at the extreme end of a room that has a high aspect ratio (long narrow room). Also
avoid installing units too close together. This tends to reduce the effectiveness of the air distribution as compared to units
located 30 to 40 ft (9 to 12 mm) apart.

2.3 Air-distribution Considerations for Downflow Units

• Verify that the raised floor has been properly sized for the unit's airflow and the room is free of airflow
restrictions.
• Perforated floor tiles in the raised floor should ensure minimal pressure loss.
• The raised floor must provide 7-1/2 in. (191 mm) of clearance.
• Ensure that there is adequate clearance above the unit for service, such as replacing filters.
• Optional plenums are available for downflow unit ducting.
• If installing units with electrically-commutated fans (EC fans), there must be 24 in. minimum clearance below
the unit to lower the fans. Fans may also remain the in unit if desired.
• A filter plenum is required for the following units: CW146, CW181, CW300, CW400.
NOTE: The floor stand used with EC units is not symmetrical and its orientation to the Liebert® CW is
critical to lowering the EC fans. Unless the floor stand is installed in the correct position, the blowers
will not lower into the floor stand.
2 Pre-installation Preparation and Guidelines
Title
Plenum Dimensional Data, DownflowModels, CW038to CW084
Plenum Dimensional Data, DownflowModels, CW106andCW114
Plenum Dimensional Data, UpflowModels, CW038to CW084
Plenum Dimensional Data, UpflowModels, CW106andCW114
Plenum Dimensional Data, UpflowModels, CW038to CW084
Plenum Dimensional Data, UpflowModels, CW106andCW114
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