11
Exhaust-air mode:
❑ The extractor-hood fan extracts the
kitchen vapours and conveys them
through the grease filter into the
atmosphere.
❑ The grease filter absorbs the solid
particles in the kitchen vapours.
❑ The kitchen is kept almost free of grease
and odours.
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.
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.
Unrestricted operation is possible if the
extractor hood is used in recirculating mode
– with activated carbon filter.
Operating modes
Circulating-air mode:
❑ An activated carbon filter must be fitted
for this operating mode (see Filters and
maintenance).
ṇThe complete installation set and
replacement filters can be obtained from
specialist outlets.
❑ The extractor-hood fan extracts the
kitchen vapours which are purified in the
grease filter and activated carbon filter
and then conveyed back into the
kitchen.
❑ The grease filter absorbs the grease
particles in the kitchen vapours.
❑ The activated carbon filter binds the
odorous substances.
ṇ If no activated carbon filter is installed,
it is not possible to bind the odorous
substances in the cooking vapours.
