Installing A Bottom-Discharge Grille For 4-Ton And 5-Ton Models; Guidelines For Ducted Systems - Vertiv Liebert Mini-Mate MT048 Installer/User Manual

6.2.4 Installing a Bottom-discharge Grille for 4-ton and 5-ton Models
The optional, bottom-discharge grille is a 3-way louvered-air grille, painted white, and added to a T-bar
grid assembly for air discharge directly into room from the bottom of the unit. Use a separate filter-box kit
for filtration and connection to field-provided room-air-return ductwork.

6.2.5 Guidelines for Ducted Systems

Observe the following for all ductwork.
• Ductwork should be fabricated and installed in accordance with local and national codes.
• Use flexible ductwork or nonflammable cloth collars to attach ductwork to the unit and to
control vibration transmission to the building.
• Attach the ductwork to the unit using the flanges provided. Locate the unit and ductwork so
that the discharge air does not short-circuit to the return-air inlet.
• Ductwork that runs through a conditioned space or is exposed to areas where condensation
may occur must be insulated. Insulation of ductwork is vital to prevent condensation during
the cooling cycle.
• The use of a vapor barrier is required to prevent absorption of moisture from the surrounding
air into the insulation.
• If the return-air duct is short or if noise is likely to be a problem, sound-absorbing insulation
should be used inside the duct.
• Ductwork should be suspended using flexible hangers. Ductwork should not be fastened
directly to the building structure.
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