GE Profile PV977 Owner's Manual And Installation Instructions page 15

CONSTRUCT CEILING SUPPORT (Continued)
• Secure each 2 x 4 block with at least four (4), #10
wood screws, 3" long (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 directions.
Check with a spirit level and adjust if necessary.
IMPORTANT: The ceiling structure must be capable
of supporting the weight of the hood (approximately
200 pounds) and any inadvertent user contact loads.
The hood support frame will be supported by the
2 x 4 cross framing.
Ductwork for Installations Vented to the Outdoors
• 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 8" round rigid duct.
• Install the house ductwork to run horizontally
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 the ceiling is level; use shims if necessary.
Installation Preparation
15
2 x 4 min.
Cross framing
8-1/4"
Ceiling joist
8"
Duct
2 x 4
Vent straight up
through the ceiling
Ceiling
joist
10-5/16"