Miele DA 2578 Operating And Installation Instructions page 50

Connection for air extraction
Recirculation mode
The silencer needs to be positioned
between the exhaust connection and
the exhaust grille . Ensure there is
adequate space for fitting it.
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.
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