User manual
13
Flow characteristics
For an ecient extraction of air cleaned of grease particles, attention
needs to be paid to the ow characteristics of the air. If possible, the
air should ow through the ducting unhindered in a constant stream.
Flow characteristics are aected by the shape and length of the
ducting. Generally speaking, round is better than square and the
smoother the surface of the ducting, the more ecient the extraction
system will be. The cross-section of the extraction ducting must,
however, be adapted to the power of the fan.
To ensure optimum performance, the installation instructions need to
be followed. Miele recommends using as short a ducting section with
as few bends as possible.
Vented mode – What needs to be considered?
Recommendations for vent ducting
If the exhaust air is extracted via a suitable ue, the extraction
ducting should always be directed in the direction of the air ow so
that the air isn't directed against the ue wall.
Hat-like covers on the vent openings hinder air ow. Ideally, air ow
should be blown out horizontally or along an appropriately shaped
cover.
The diameter should be as large as possible and constant along
the entire length of the ducting. Constrictions worsen the extraction
performance and increase sound levels.
Bends with sharp-edged angles and kinks should be avoided. Soft
radii reduce noise and have less performance loss.
1.
2.
3.
4.
Smooth-walled ducting, i.e.
plastic or PVC or metal
Semi-rigid aluminium exible with
low wave height
Smooth rectangular ducting
Highly exible duct with large
wave height
good
sucient
unsuitable
Miele recommends
Large diameters and smooth-walled ducting
generate optimum air ows, minimise turbulence
and thus reduce noise development.
Miele recommends min 150 mm.
very good
13
NB These recommendations must be viewed in conjuction with the overriding local and national
building codes and regulations.