Miele T 4322 Operating Instructions Manual page 37

Friction against the inner walls of the
ducting will slow down the expelled air
as it passes through. An elbow, bend,
non-return flap or wall vent creates
more friction than a straight duct. The
friction created by each of these is
expressed as an
. The additional length
factors are calculated by comparing
the friction created by, for example, an
elbow to that created by 1 metre of
straight plastic piping (Table I).
The additional duct length factor for
each item needs to be added together
to ascertain the
required.
A larger
helps reduce friction. If the effective
duct length is
duct diameter should be increased
(Table II).
^ First measure the distance which will
require straight ducting. Multiply this
amount by the corresponding
additional duct length factor in
^ Establish the number of angles,
bends etc. necessary and add their
additional duct length factors
together with the help of
^ Add all the additional duct length
factors together to get the effective
duct length.
^ Refer to
duct diameter required.
–
1 m laid straight
–
45° angle
(Bend radius = 0.25 m)
–
90° angle
(Bend radius = 0.25 m)
–
1 m laid straight / or 1 m
straight pipe
–
45° angle / elbow
(Bend radius = 0.25 m)
–
90° angle / elbow
(Bend radius = 0.25 m)
also
–
with louvred grille
the
–
with non-return flap (hinged
flap)
*optional accessory from Miele
.
.
for the appropriate
20 m
40 m
100 m
1.8 m
1.5 m
2.5 m
1.0 m
0.6 m
0.8 m
3.8 m
1.5 m
14.3 m
11.0 m
1.0 m
100 mm
125 mm
150 mm
37