GE ZV850 - Manual (Page 7)

7
Installation Preparation
36" Island Vent Hood
Advance
Planning
(continued)
1
Step
Ductwork
• Use the shortest and straightest duct route
possible. For satisfactory performance, duct
run should not exceed 100 feet equivalent
length for any duct configuration.
• Refer to “Duct Fittings” chart to compute the
maximum permissible length for duct runs
to the outdoors.
• This vent hood must use 6” round duct. The
6” round duct can transition to 3-1/4” x 10”
or 3-1/4” x 12”.
• Install the house ductwork to run horizon-
tally between ceiling joists or straight up
through the roof.
Finish the Ceiling
Finish the ceiling surface. Be sure to mark
location of the ceiling joists and cross framing.
Check to be sure that ceiling is level, use shims
if necessary.
• Arrange cross framing in the ceiling to suit
the existing structure. See examples.
– Secure each 2 x 4 block with at least four (4),
#10 wood screws, 3” long (minimum size
screws, not supplied). Use 8 wood screws
total for the two supports.
• The cross framing must be accurately aligned
to assure correct positioning of the hood.
• The cross framing must be level in all direc-
tions. Check with a spirit level and adjust if
necessary.
IMPORTANT: The ceiling structure must be capable of supporting
the weight of the hood (approximately 100 pounds) and any
inadvertent user contact loads. It is recommended that the hood
support frame be supported by a minimum of 2 x 4 cross framing.
Ceiling Joint
2x4
6"
Duct
Vent Straight Up
Through The Ceiling
Flat
Vent Between
Ceiling Joists
Standing
6" Round
Duct Elbow
Support
Frame
Opening
Upper Half
Of Support
Frame
Ceiling
Joist
Cross Framing
Height
Adjustment
Slot
Front
of
Hood
7-5/8"
8-3/4"