________________________________________________________________________________
87
AST 14 C 255/00
SECT. 7
VENT DUCTS AND PIPES
For intake/flue gas vent lines use only original ducts designed for the specific boiler (as per
manufacturer's specifications).
7.1 100/60 CO-AXIAL AIR/VENT DUCTS
Dimensions for connection of flue gas duct to co-axial pipes
Type C12
Type C12 horizontal vent
The minimum permissible length of horizontal coaxial pipes is 0.5 metres, including the
first elbow connected to the boiler.
The maximum permissible length of horizontal coaxial pipes is 6 metres for 24 kW models,
7 metres for 28 kW models and 5 metres for 32 kW models, excluding the first elbow
connected to the boiler.
For each additional 90° elbow, maximum permissible length is to be reduced by 1 metre,
whereas for the 45° one by 0.5 metres. The duct is to be tilted down by 1% toward its
outlet, to prevent rain water from entering it.
Using the diaphragms supplied with the boiler (pic. 1)
Flue gas vent diaphragms:
Pipe length [m]
Flue gas vent diaphragm diameter [mm]
CTFS 24
CTFS 28
CTFS 32
0.5
≤
L
≤
2*
39.8
39
39.8
2 < L
≤
3*
42
41
41
3 < L
≤
4*
45
44
4 < L
≤
5*
49
47
47
5 < L
≤
6*
-
Not allowed
6 < L
≤
7*
Not allowed
-
*
Excluding the first elbow
