English 9
PLAN THE INSTALLATION
Note:
The manufacturer is not responsible for performance
complaints attributable to the duct section.
•
The device achieves its optimum performance by means of a
short, straight exhaust air duct and as large a pipe diameter as
possible.
•
The optimum extraction performance is not achieved and fan
noise is increased if exhaust air ducts are long and rough and if
there is a large number of duct bends or diameters less than 6”
(152mm).
•
The pipes or hoses for laying the exhaust air line must consist of
non-combustible material.
•
Seal the connection points of the ducts appropriately.
•
Ductwork must vent outside, not into attic spaces for example,
unless the available ‘Non-duct Recirculation Kit’ is used.
Select ducting option
The 5 basic discharge connections, left, right, rear, front and
recirculation can be achieved through A to F with the optional
parts listed.
1. The downdraft blower system is designed for use with
8” (203mm) round ductwork using a lexible blower or
6” (152mm) round ductwork using an inline or remote blower.
(Purchase blowers separately.): Six (6) different discharge
connections are available - A to F, below:
A = 8” (203mm) Round, Left Discharge out of Flex Blower
B = 8” (203mm) Round, Right Discharge out of Flex Blower
C = 8” (203mm) Round, Down Discharge out of Flex Blower
(Electrical Panel to be mounted remotely)
D = 1-7/8” x 19” (48mm x 483mm), Left Discharge out of
Housing to Remote Blower or Flex Blower in remote location.
Use 1-7/8” x 19” (48mm x 483mm) to 6” or 8” (152mm or
203mm) round transition ductwork as appropriate.
E = 1-7/8” x 19” (48mm x 483mm), Right Discharge out of
Housing to Remote Blower or Flex Blower in remote location.
Use 1-7/8” x 19” (48mm x 483mm) to 6” or 8” (152mm or
203mm) round transition ductwork as appropriate.
F = 1-7/8” x 19” (48mm x 483mm), Rear Discharge out of
Housing to Remote Blower or Flex Blower in remote location.
Use 1-7/8” x 19” (48mm x 483mm) to 6” or 8” (152mm or
203mm) round transition ductwork as appropriate.
2. For best performance: Choose the ducting option which allows
the shortest length of ductwork and a minimum number of
elbows and transitions. Check location of loor joists, wall
studs, electrical wiring or plumbing for possible interference.
A
B
C
D
E
F
Ductwork Preparation
DUCTING RECOMMENDATIONS
Proper performance is dependent upon proper ducting.
Local building codes may require the use of make-up air
systems when using ducted ventilation systems greater
than speciied cubic feet per minute (CFM) of air movement.
The speciied CFM varies from locale to locale. It is the
responsibility of the owner and the installer to determine if
additional requirements and/or standards apply to speciic
installations.
DO NOT USE FLEXIBLE DUCT; it creates back pressure/
air turbulence and reduces performance.
Always install a metal vent cover where the ductwork exits
the house.
COLD WEATHER installations should have an additional
backdraft damper installed to minimize backward cold air
low and a nonmetallic thermal break to minimize conduction
of outside temperatures as part of the ductwork.
The damper should be on the cold air side of the thermal
break. The break should be as close as possible to where
the ducting enters the heated portion of the house.
MAKE-UP AIR: Local building codes may require the use of
make-up air systems when using ducted ventilation systems
greater than speciied CFM of air movement. The speciied
CFM varies from locale to locale. It is the responsibility
of the owner and the installer to determine if additional
requirements and/or standards apply to speciic installations.
For safety reasons, ducting should vent directly outdoors
(not into an attic, underneath the house, into the garage
or into any enclosed space). The unit cannot be used in
conjunction with a recirculation unit.
BOSCH
®
recommends not exceeding 50 ft. (15 m) of
equivalent duct.
Plan cabinetry
For left, right, or rear exhaust:
Allow at least 18” (457mm) for transition and elbow or blower.
For left / right exhaust:
A 30” (762mm) deep cabinet is recommended to align
properly with lex blower. Flex blower can be mounted to
rear cabinet wall or to a platform / frame (not provided) on
the base of the cabinet loor. (See lex blower instructions.)
Cabinet depths of 24” (610mm) to 30” (762mm) are
required - depending on the type of cooking appliance.
For some applications, gas or electrical connections will
need to be moved or routed around downdraft unit.
For gas cooktop installations make sure that a minimum
27 square inch (174 cm
2
) opening is provided in the
toe-kick and cabinet base. Inadequate ventilation of the
cabinet below the cooktop may result in lame outage when
operating the fan on higher speeds.
Note:
A cooktop sealing kit must be purchased for gas
applications. The kit includes hole covers for the toe-kick
and cabinet base, as well a a trim seal for the cooktop.
