Installation of roof mounted unit arrangement dbc, Install combination curb adaptor, Install curb/equipment support(s) – Greenheck DG / DGX with Direct Spark (470652) User Manual
Page 5: Install ductwork, Install exhaust options, Apply sealant, Install exhaust fan

Direct Spark Ignition Make-Up Air
5
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2. Install Combination Curb Adaptor
Install combination curb adaptor over curb, use wood
screws to lag in place. Locate extension so the tall
louvered side is over the exhaust opening, as shown
in illustration. Caulk extension to combination curb
adaptor. Fasten extension to curb adaptor with #12
sheet metal screws (field-provided).
1. Install Curb/Equipment Support(s)
Position curb/equipment support(s) on the roof
(reference the CAPS submittal for placement of curb/
equipment support(s) in relation to the unit). Verify that
all unit supports are level, shim if necessary. Attach
curb to roof and flash into place. Attach the equipment
support(s) to the roof, remove metal cover, flash to
wooden nailer and reinstall cover.
Installation of Roof Mounted Unit
Arrangement DBC
3. Install Ductwork
Good duct practices should be followed for all
ductwork. All ductwork should be installed in
accordance with SMACNA and AMCA guidelines,
NFPA 96 and any local codes. Reference the CAPS
submittal for ductwork size and location.
NOTE
The use of a duct adapter is recommended on a
downblast (DBC) arrangement to align the ductwork
with the supply unit. The duct adapter is only a guide
and is not to be used as a support for the ductwork.
Exhaust
Supply
1 inch
Inside Flange
Combination Extension
Supply
Ductwork
by Others
Exhaust
Ductwork
by Others
Ductwork
6. Install Exhaust Options
Install optional hinge kit with restraining cables and
grease trap with drain connection.
4. Apply Sealant
Apply an appropriate sealant around the perimeter of
the curb and duct adapter(s) to isolate fan vibration and
prevent water penetration.
NOTE
NFPA 96 requires the exhaust fan to be hinged.
Supply Duct with
Duct Adapter Installed
Exhaust Duct Installed
Sealant
Sealing Ductwork
Exhaust Fan
Installing Exhaust Fan
Metal Cover
Equipment
Support
Roof Curb
Curb and Equipment Support
5. Install Exhaust Fan
Fasten exhaust fan to curb extension with self-tapping
sheet metal screws. Installing the exhaust fan prior
to the supply unit will allow for easier installation of
options.