Bosch HUI31451UC - Manual (Page 7)

Installation
English 5
Ducting Recommendations The unit is for ducting to the outside; it cannot be used in conjunction with a recir-
culation unit.
For the most efficient air flow exhaust, use a straight duct run or as few elbows as
possible.
Do not use flex ducting. Always use metal ductwork with a diameter of 6” (150
mm).
COLD WEATHER installations should have an additional backdraft damper
installed to minimize backward cold air flow 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.
Always install a metal vent cover where the ductwork exits the house.
Make-Up Air: Local building codes may require the use of make-up air systems
when using ducted ventilation systems greater than specified CFM of air move-
ment. The specified CFM varies from locale to locale. Consult your HVAC profes-
sional for specific requirements in your area.
Installation Procedure
WARNING: To avoid electrical shock hazard, before installing,
switch power off at the service panel and lock the panel to prevent the
power from being switched on accidentally.
Unpack Hood
Pull hood from outer packaging. Remove and discard all packaging materials.
Remove filter and set aside (See Use and Care manual for removal instructions).
Prepare ductwork
Install one-way damper so that the flap opens up (snaps into place). Note: verify
that the flap opens up (toward the ceiling) before continuing. If necessary, install
thermal break and additional backdraft damper.
Figure 8: Housing Cutout Dimensions - 28 3/4” (73 cm) models
5/8” (16 mm)
5/8”
(15
mm)
min.
13 7/8”
(325.3
mm)
5/8”
(15 mm)
min.
27 5/8”
(700.3
mm)