20
Prior to installation
Exhaust-air mode
A central ventilation system extracts
kitchen vapours and passes them through
the grease filter to the outside.
For this to work the building’s ventilation
system must be operating and the air flap
open in the extractor hood.
D
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.
D
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.
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.
