Air-Distribution Considerations For Upflow Units; Upflow Ducting Configurations (Forward-Curved Blowers) - Vertiv Liebert CW Series Installer And User Manual

2.4 Air-distribution Considerations for Upflow Units

Various configurations are available:
• Front return
• Rear return
• Bottom return (not available on CW106 and CW114 models)
For in-room applications with supply and return grilles, several feet of clearance must be maintained at the intake and
discharge of the unit.
Upflow rear-return configurations use a filter box attached to the back of the unit. Allow 25 in. (635 mm) on one side of the
unit for access to the rear-return filter box. Refer to the rear-return installation sheet, inside the rear-return filter box
package.
For ducted applications, duct flanges are supplied on the blower outlets. Follow the SMACNA-Duct Construction Standard
for single-, dual-, or triple-blower systems. Do not run duct work off the perimeter flange on the top of the unit. This flange is
for positioning and attaching the optional air discharge plenum with grille. Attaching a duct to this flange may reduce
airflow to inadequate levels.
Figure 3.2 Upflow ducting configurations (forward-curved blowers)
NOTE: Drain traps are qualified to a return duct static of negative 1.5 i.w.g. (-1.5 i.w.g).
2 Pre-installation Preparation and Guidelines
Item Description
1 Typical ducting
2 Straight sectionsmust be 1.5 to 2.5 timesthe longest blower dimension.
3 Front of unit
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