Viessmann vitodens Technical Manual page 124

4.2 Design and sizing information for flue pipe connections
Max. total length of the flue pipe
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
and 0.5 m length of union D.
4
124
kW
m
kW 4.5 12.0
m 15
m
m
For any different number of bends,
deduct from/add to the given max. length
1 m for 87º bends or 0.5 m for 45º bends.
For a different length of union D, deduct
or add 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 1 m length of union D:
Deduct 1 m for the bend and 0.5 m for the
union from the max. flue pipe length of
20 m.
Consequently, the max. length would be
18.5 m.
8.8 26.0
20
16.6 66.0
25 15
VITODENS