Ductwork; Roof Curb - Trane YSC060 Installation Operation & Maintenance

RT-SVX31A-EN
Installation

Ductwork

Figure 4-1 illustrates the supply and re-
turn air openings as viewed from the
rear of the unit.
Elbows with turning vanes or splitters
are recommended to minimize air noise
due to turbulence and to reduce static
pressure.
When attaching the ductwork to the
unit, provide a water tight flexible con-
nector at the unit to prevent operating
sounds from transmitting through the
ductwork.
All outdoor ductwork between the unit
and the structure should be weather
proofed after installation is completed.

Roof Curb

Note:
All Gas/Electric units shall be installed
on a roof curb that is a minimum height
of 5.0 inches ( 127 mm ), or in any other
manner such that the distance between
the bottom of the intake vents of the gas
section and grade of the surface that the
unit is installed on is no less than 19.7
inches ( 500 mm ).
Downflow
The roof curbs for these units consists
of a "full perimeter" enclosure to sup-
port the unit.
Before installing any roof curb, verify;
1. That it is the correct curb for the unit,
2. That it includes the necessary gas-
kets and hardware,
3. That the purposed installation loca-
tion provides the required clearance
for proper operation.
4. Insure that the curb is level and
square. The top surface of the curb
must be true to assure an adequate
curb-to-unit seal.
Step-by-step curb assembly and instal-
lation instructions ship with each acces-
sory roof curb kit. Follow the instruc-
tions carefully to assure proper fit-up
when the unit is set into place.
Note:
To assure proper condensate flow
during operation, the unit (and curb)
must be level.
If the unit is elevated, a field con-
structed catwalk around the unit is
strongly recommended to provide easy
access for unit maintenance and ser-
vice.
Recommendations for installing the
Supply Air and Return Air ductwork join-
ing the roof curb are included in the
curb instruction booklet. Curb ductwork
must be fabricated and installed by the
installing contractor before the unit is
set into place.
Note:
For sound consideration, cut only the
holes in the roof deck for the ductwork
penetrations. Do not cut out the entire
roof deck within the curb perimeter.
If a Curb Accessory Kit is not used:
a. The ductwork can be attached
directly to the factory-provided
flanges around the unit's supply
and return air openings. Be sure
to use flexible duct connections
at the unit.
b. For "built-up" curbs supplied by
others, gaskets must be installed
around the curb perimeter flange
and the supply and return air
opening flanges.
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