Component Installation Requirements
Connections made directly to the discharge opening of a housed fan should have a minimum of
three fan diameters of straight duct before any turns or transitions. The ductwork should be the
same size as the fan discharge opening. The first turn of the connection should be in the same
direction as the fan rotation as shown in
extremely turbulent and requires some length of duct to stabilize. Abrupt changes in ductwork
directly off the fan discharge may adversely affect fan performance and acoustics.
Figure 57. Typical discharge ductwork recommendations
Splitters or
turning vanes
Damper Connections
For standard damper sections, size the attached ductwork to fit the opening of the damper. The duct
opening dimensions should be in the unit submittals. Ensure the insulation does not obstruct the
damper opening when using a lined duct (see
Figure 58. Typical section with duct flat/flange connection-
uninsulated or externally insulated
72
Vane turns in same
direction as fan rotation
Figure
57. The air that the fan discharges into the duct is
Figure 58
and
Figure
Figure 59. Typical section with duct flat/flange connection-
internally insulated
59).
CLCH-SVX07C-EN