GE JGP990 - Manual (Page 23)

PREPARE FOR DUCTWORK
NOTE: Ductwork MUST be vented outside. DO
NOT vent into a wall, ceiling, crawlspace, attic or
any concealed space.
Determine the best route for ductwork; it can be
routed in a variety of ways depending on the
kitchen layout.
IMPORTANT: The downdraft air discharge outlet
for this unit is 3-1/4
″ x 10″ rectangular. Plan
ducting accordingly.
Typical duct arrangement countertop series.
23
Installation Instructions
BLOWER TO DUCTWORK
ALIGNMENT
In general, the use of flexible ducting is discouraged
because it can cause severely restricted airflow.
However, if the blower outlet and the floor or wall duct
location do NOT align well, then flexible METAL
ducting can be used to adapt to an offset. Good
alignment without use of flexible ducting is best.
NOTE:
Do not exceed the maximum recommended
offset of 6
″.
Do not allow the flexible ducting to kink or
collapse.
Do stretch the flexible ducting as much as
possible to eliminate as much of the corrugation
as possible.
A 3 1 ⁄
4
″ x 10″ rectangle to 6″ round transition duct
is available at your local building supply store.
NOTE: Illustrations are for planning purposes only.
Inside wall
cabinet
Up inside wall to roof
or overhang
Directly to outside
Between floor joists Through cabinet toe space
Peninsula or island
Peninsula
Outside wall
cabinet
NOTE: PVC sewer pipe type PSM 12454-B
Schedule 40 ASTM D1785.
Wall Cap Concrete
Slab
6 ″ (15 cm)
Dia. PVC
Sewer Pipe
6 ″ (15 cm)
Dia. Metal
Duct
Pack tightly with gravel
or sand completely
around pipe
3-1/4 ″ x 10″ Rectangular
to 6 ″ Round Transition
6 ″ (15 cm)
Dia. 90 °
Metal Elbow
6 ″ (15 cm) Dia.
Metal Duct
16 ″
(40.6 cm)
Max.
12 ″
(30 cm)
Min.
6 ″
(15 cm)
Dia. PVC
Coupling
6 ″ (15 cm) Dia.
PVC Sewer Pipe
Elbow
6 ″ (15 cm) Dia.
PVC Sewer Pipe
Elbow
6 ″ (15 cm)
Dia. PVC
Sewer
Pipe
6 ″
(15 cm)
Dia.
PVC
Coupling
30 ′-0″ (9.14 m) Max.
6
Optional duct arrangement under concrete slab.
PVC duct should be used if installing under a
poured concrete slab.
7
PREPARATION
Back Venting
(Requires 3 1 ⁄
4
″ x 10″)
Bottom Venting
6 ″ Max.
Centerline
to Centerline
Offset