Siemens LC 85 K 950 Operating And Installation Instructions page 22

Installation Instructions
The exhaust air is discharged upwards
through a ventilation shaft or directly through
the outside wall into the open.
Exhaust air should neither be directed into
a smoke or exhaust flue that is currently
used for other purposes, nor into a shaft
that is used for ventilating rooms in which
stoves or fireplaces are also located.
Exhaust air may be discharged in
accordance with official and statutory
regulations only (e.g. national building
regulations).
Local authority regulations must be
observed when discharging air into smoke
or exhaust flues that are not otherwise in
use.
When the extractor hood is operated in
exhaust-air mode simultaneously with a
different burner which also makes use of
the same chimney (such as gas, oil or coal-
fired heaters, continuous-flow heaters, hot-
water boilers) care must be taken to
ensure that there is an adequate supply
of fresh air which will be needed by the
burner for combustion.
Safe operation is possible provided that the
underpressure in the room where the burner
is installed does not exceed 4 Pa (0.04
mbar).
This can be achieved if combustion air can
flow through non-lockable openings, e.g. in
doors, windows and via the air-intake/
exhaust-air wall box or by other technical
measures, such as reciprocal interlocking,
etc.
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 ovens.
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