Viessmann vitodens Technical Manual page 108

4.2 Design and sizing information for flue pipe connections
Max. total length of the flue pipe to the flue outlet
Vitodens 200
Rated output range
Max. length system size 80
Vitodens 300 and Vitodens 333
Rated output range
Max. length system size 60
Max. length system size 80
Max. length system size 100
Allowed for: 2 bends of 87º
(incl. support bends)
or 3 bends of 45º
0.5 m length of union D and an internal
duct dimension of
H 120 × 120 mm at system size 60
H 150 × 150 mm at system size 80
H 170 × 170 mm at system size 100.
4
108
kW
m
kW 4.5 12.0
m 15
m
m
For a different number of bends, deduct
from/add to the given max. length 1 m for
87º bends, 0.5 m for 45º bends or 2 m for
inspection tees.
For a different length of union D, deduct
or add twice the difference.
6.6 26.0 8.7 35.0 12.2 49.0
20 15
Example:
Vitodens 300, 6.6 26.0 kW, with 3 bends
87º and 2 m length of union D:
Deduct 1 m for the bend and 3 m for the
union from the max. flue pipe length of
20 m.
Consequently, the max. length would be
16 m.
8.8 26.0
20
16.6 66.0
20 15
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