Miele KWT4154UG1 - Manual (Page 14)

Air exchange through the
activate charcoal filter
External air passes through the filter
before entering the unit.
The active charcoal filter ensures that
only clean, odor-free air enters the unit,
creating additional protection against
odor contamination.
The filter will need to be changed
periodically, or when odors are
present in the unit. See "Cleaning
and Care - Active charcoal filter" for
more information.
Optimum temperature and air quality
14