5
Design Information
Downdraf t Vent Systems
Advance
Planning
(continued)
Clearances
• The downdraft system with blower, motor
and ductwork will occupy the cabinet below
the countertop and cooktop.
• The blower/motor assembly can be located
below the cabinet floor. The assembly will fit
between 16" floor joists. Order JXRB57 for
indoor remote locations.
– In this installation a transition to 6" round
is required.
• The blower motor assembly can also be
installed outdoors. Order JXBC57 for
remote blower installations outdoors.
– In this installation one or two 3-1/4"x10"
to 6" round transitions may be required.
• Refer to “Cooktop Clearances” for informa-
tion on appropriate placement and neces-
sary clearances when planning installation.
• Refer to your specific cooktop installation
instruction for other appropriate clearances.
• Avoid placing cabinetry directly above the
cooking surface when possible.
Ductwork
Prepare ductwork to vent to the outdoors.
• Use the shortest and straightest duct run
possible.
– The maximum permissible length for duct
run is 150 feet.
– Refer to “Duct Fittings” chart to calculate
equivalent length for various duct
configurations.
Electrical and Gas Locations
Plan the placement of the electrical outlet and
gas (if used) carefully. Gas or electrical outlets
cannot be placed on the back wall of the
cabinet because it may interfere with the
downdraft plenum.
• Install a standard electrical outlet within
reach of the vents’ two foot long power
cord.
– The vent and a Monogram gas cooktop
combination can operate from the same
120 volt standard duplex outlet.
– Electric cooktops must operate from a
separate 240 volt junction box.
• If cabinetry is used above the cooking
surface:
– Use cabinets no more than 13" deep.
– Maintain 30" minimum clearance between
cooktop and unprotected cabinets directly
above cooktop.
– If clearance is less than 30", protect
cabinet bottoms with flame-retardant
millboard at least 1/4" thick or gypsum
board at least 3/16" thick covered with 28
gauge sheet steel or .02" thick copper.
– Clearance between cooktop and protected
cabinetry must not be less than 24."
EXCEPTION: Installation of a listed micro-
wave oven or cooking appliance over the
cooktop shall conform to the installation
instructions packed with that appliance.
– Working areas adjacent to the cooktop
should have 18" minimum clearance
between countertop and cabinet bottom.
• Installation must conform with local codes.
• The downdraft blower system is designed to
use 3-1/4" x 10" ductwork. It can be
transitioned to 6" round.
• Ductwork MUST be vented to the outside–
never into a crawl space, attic or other
enclosed space.
• Determine the need for a wall cap or roof
cap. Order the cap in advance.