16
Installation of Secondary Supply Duct
Figure 18. Typical Duct Knockout
A limited amount of conditioned air can be diverted
through a small duct to a location outside of the zone. For
example, a common application is for the cassette unit to
serve an office that has a small attached bathroom. Air
can be supplied to the bathroom from the cassette unit by
following these instructions.
NOTE -
Secondary supply duct knockouts are located on
all four sides of the V33B cassette body. If the knock out
is used, the supply air opening of the same side should be
blocked and sealed.
1. Decide which side of the cassette body will be ducted.
2. Seal the supply air outlet on the side to which the duct
will be attached. See the Supply Air Configurations
section for detailed instructions.
3. Knockout the secondary supply duct opening. See
Figure 18.
4. Remove any insulation.
5. Connect the secondary supply duct to the cassette
body using the eight screw holes shown in figure 18.
6.
A field-supplied duct transition may be required. Be
sure there is an air-tight seal between the transition
and the cassette body and between the transition and
the secondary supply duct.
7. The secondary supply duct must be 4 or 6 inches
in diameter and 10 feet or less in length (including
transitions).
NOTE -
A field-supplied volume control damper can be
used to control the amount of air supplied to the space,
however, the area being conditioned by the secondary
supply duct will not have control over the temperature of
the air being supplied.
Duct Knockouts
Supports
Drop Ceiling
NOTE - The secondary supply duct must be 4 or 6 inches in diameter and 10 feet or less
in length (including transitions).
Supply Duct
10 feet maximum
Seal supply air outlet on duct side
Typical cassette body shown, actual unit may vary in
size and location of secondary duct knockouts.
Figure 19. Supply Duct Maximum Length
