Wolf CGB-75 Assembly And Operating Instructions Manual page 42

Minimum duct sizes
applicable to open flue and balanced flue operation
C93x balanced flue in a duct
DN 110
4
C93 x balanced flue
System DN 110/160
horizontal and DN 110
vertical
Balanced flue, rigid in a duct
Min. duct sizes
Round Ø
DN 110 190 mm
DN 160 250 mm
42
Design information
>20
Square
170 mm
230 mm
5
C33x balanced flue
in a duct DN 110/160
B33 open flue
in a duct DN 110
B33
3062555_201507
>30