Mammoth V-Cube Slim E-Series (Standard Versions) - Manual (Page 7)

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MAMM-VCS-IOM-1EB (October 2011)
Ductwork and Attenuation
Discharge ductwork is normally used with the V-Cube
Slim™. Return air ductwork may also be required.
All ductwork should conform to industry standards
of good practice as described in the ASHRAE Systems
Guide.
The discharge duct system will normally consist of
a flexible connector at the unit connection, a transition
piece to the full duct size, a short run of duct,
and elbow with vanes, and a trunk duct teeing into
a branch duct with discharge diffuses. The transition
piece must not have angles totaling more than
30° or severe reduction in airflow performance can re-
sult. Do not connect the full duct size to the unit. Use a tran-
sition piece sized according to the discharge collar on
the unit to get to the full duct size. With metal duct ma-
terial, the sides of only the elbow and entire branch
duct should be internally lined with acoustic fibrous in-
sulation for sound attenuation. Glass fiber duct board
material is more absorbing and may permit omission of
the canvas connector.
The ductwork should be laid out so that there is no
line of sight between the unit discharge and
the distribution diffusers.
Return air ductwork (if used) should be connected to
the unit using the filter section flange..
Ventilation Air
Outside air may be required for ventilation. The tem-
perature of the ventilation air must be controlled so that
the mixture of outside air and return air entering the
unit is within application limits. It is typical to close off
the ventilation air system during unoccupied periods
(i.e. night setback).
The ventilation air system is typically a separate build-
ing subsystem with distribution ductwork. Simple intro-
duction of the outside air into each return air plenum
chamber reasonably close to the unit air inlet is
recommended. Do not duct outside air directly to the
unit inlet. Provide sufficient distance for the thorough
mixing of outside and return air.