Bosch DHI 655 F Mode D'emploi Et Notice De Montage page 23

Prior to installation
Exhaust-air mode
The exhaust air is discharged upwards
through a ventilation shaft or directly
through the outside wall into the open.
D Exhaust air must not be discharged via
a smoke or exhaust gas flue which is
already in use or via a shaft which is used
for ventilating rooms in which fireplaces are
located.
Discharge exhaust air in accordance
with official and statutory regulations
(e.g. national building regulations).
Discharge of air into smoke or exhaust air
flues which are not in use requires the
consent of a heating engineer.
D
If the extractor hood is operated in
exhaust-air mode at the same time as a
flue-type heater (e.g. gas, oil or solid-fuel
heater, instantaneous water heater, boiler),
ensure that there is an adequate air
supply which the heater requires for
combustion.
Safe operation is possible provided that the
partial vacuum in the room in which the
heater is installed does not exceed 4 Pa
(0.04 mbar).
This can be achieved if the combustion air
is able to flow through non-lockable
openings, e.g. in doors, windows and in
conjunction with an air supply/air-intake wall
box or by other technical procedures such
as reciprocal interlocking.
If the air intake is inadequate, there is a
risk of poisoning from combustion gases
which are drawn back into the room.
An air-intake/exhaust-air wall box by itself is
no guarantee that the limiting value will not
be exceeded.
Note: When assessing the overall
requirement, the combined ventilation
system for the entire household must be
taken into consideration. This rule does not
apply to the use of cooking appliances,
such as hobs and gas cookers.
The extractor hood can be used without
restriction in circulating air mode – with an
activated carbon filter.
For exhaust air mode a one-way flap
should be installed in the extractor hood
unless already installed in the exhaust air
pipe or wall box.
If a one-way flap is not enclosed with the
extractor hood, you purchase one from
your dealer.
If the exhaust air is conveyed through
the outside wall, a telescopic wall box
should be used.
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