Unit installation

Installation - Mechanical
30 SCXF-SVX01K-EN
Duct Connections
Return air enters the rear of the unit and conditioned
supply air discharges through the top. Attach supply air
ductwork directly to the unit’s top panel, around the fan
discharge opening. A duct collar is not provided.
Note: Units equipped with flexible horizontal discharge
plenum option may include a duct collar when
holes are factory cut. If discharge openings are
field-cut, refer to the “Plenum Installation” section.
Install all air ducts according to the National Fire Protection
Association standards for the “Installation of Air
Conditioning and Ventilation Systems other than
ResidenceType (NFPA 90A) and ResidenceType Warm Air
Heating and Air Conditioning Systems (NFPA 90B).
Make duct connections to the unit with a flexible material
such as heavy canvas. If a fire hazard exists,Trane
recommends using Flexweave 1000, type FW30 or
equivalent canvas. Use three inches for return duct and
three inches for discharge duct. Keep material loose to
absorb fan vibration.
Note: Compressors and fan assembly are internally
isolated. External isolation devices (spring
mounting isolators) are at discretion of a vibration
specialist consulted by building or HVAC system
designer.
• If using return ductwork to the unit, secure it with three
inches of flexible duct connector.
• Extend discharge duct upward without change in size
or
direction for at least three fan diameters.
• Use 3” flexible duct connection on discharge
ductwork.
Plenum
Before installing plenum, attach insulation strip that ships
with plenum. See Figure 22, p. 30 for proper insulation
location. Align plenum front with control panel side of
unit. Using strips and screws provided, secure plenum to
unit.Treat field-cut holes to prevent fiberglass from
entering the airstream.
Note: Plenum insulation must be applied properly to
prevent air bypass around the plenum. See
Figure 22, p. 30.
Figure 21. Duct connection recommendations
Run the ductwork straight from the opening for a minimum of
three
fan diameters. See Figure 21, p. 30. Extend remaining
ductwork as far as possible without changing size or direction.
Do not make abrupt turns or transitions near the unit due to
increased noise and excessive static losses. Use elbows with
splitters or turning vanes to minimize static losses.
Poorly constructed turning vanes may cause airflow generated
noise. Align the fan outlet properly with the ductwork to
decrease noise levels in the duct and to increase fan
performance.To complete trunk ductwork to the VAV terminal
units, refer to the VAV box manuals for specific requirements.
Check total external static pressures against fan characteristics
to be sure the required airflow is available throughout the
ductwork.
To achieve maximum acoustical performance, minimize the
duct static pressure setpoint
3 Fan
Diameters
Discharge
Duct
3-inch
Flexible
Duct
Return
Air
Figure 22. Correct plenum insulation placement
Plenum Bottom View
Dashed line indicates correct insulation placement.