IM 777-18 • SKYLINE OUTDOOR AIR HANDLER 18 www.DaikinApplied.com
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Face and Bypass Section Mounting
Internal and external face and bypass sections are mounted
together using the instructions for horizontal components
and do not require additional instruction. Skyline air handlers
are provided with a bypass duct that is integral to the unit
construction and requires no field assembly.
Face and bypass dampers may or may not be linked together.
When dampers are placed before a single bank of coils, they
always are linked together and require a single actuator. When
dampers bypass a stacked or staggered coil, the dampers are
not linked and require multiple actuators.
Face and bypass dampers have a torque requirement of 10
in-lbs per square foot of damper face area.
Isolation Dampers for Multiple Fans
Optional isolation dampers can be provided on multiple fans
to prevent backflow through a fan that is turned off for service.
These isolation dampers are not intended to be used to control
flow through the fan. The isolation damper for a fan that is
going to be started must be positioned in the full open position
before the fan is started. Do not start a fan with the damper
located at the inlet with the damper fully or partially closed.
This can cause airflow, vibration, and sound problems that can
lead to failure.
Isolation dampers can be provided with actuators that are
mounted in the airstream. Actuator sizing for the isolation
dampers should be based on 9 in-lb per square foot of damper.
Piping Vestibules
The Skyline air handler has 2 options for piping vestibules. The
curb ready base unit has a factory installed vestibule and the
unitized base option has a field installed vestibule. See order
for details.
For units that include a piping vestibule, cut the openings for
routing the field piping as required in the field. Carefully seal
passages cut through the panels to prevent air leakage. A
single metal thickness pan is provided in the bottom of the
curb-mounted vestibule. The pan can be removed if necessary.
If holes are cut into the pan for a piping passage, seal the
holes to prevent moisture leakage (
).
Figure 39: Seal Holes for Piping—Curb Mounted Units
For units with standard base rails, the vestibule is open to the
coil section; therefore, seal all holes to prevent air leakage.
Figure 40: Seal Holes for Piping—Standard Base Rail Units
Seal holes
cut for piping
Seal holes
cut for piping
