Miele DA 420V-6, Operating Instructions Manual, Page: 431 / 448

Connection for air extraction
51
 When ducting is horizontal it must be
laid to slope away at at least 1 cm per
metre. This is to ensure that
condensate cannot drain back into
the rangehood.

If the exhaust ducting is to run
through rooms, ceiling space etc.
where there may be great variations
in temperature between the different
areas, the problem of condensation
will need to be addressed. The
exhaust ducting will need to be
suitably insulated.
Silencer
To achieve even further reductions in
noise levels, a special silencer (optional
accessory) can be fitted in the ducting
system.
Air extraction mode
The silencer not only reduces noise
from the motor outside the house, but
also sounds from outside (e.g. traffic
noise). For this reason, the silencer
must be positioned as close as possible
to the ducting exit
 .
Air extraction with external motor
To minimise noise from the motor in the
kitchen, the silencer should be
positioned in front of the external motor

if possible, or, if the ducting is long,
above the exhaust connection inside
the rangehood
 . In the case of an
external motor located inside the house,
fitting a silencer behind the external
motor
 reduces the noise of the motor
outside the house.