2.8
COAXIAL DUCT
“25/60 BF -30/60 BF”
The coaxial inlet and outlet duct ø 60/100
is supplied in a kit code 8084805 complete
with mounting instructions.
2.8.1
Diaphragm installation
The diaphragm is supplied together with the
“30/60 BF”
boiler version.
See figure 9 for the positioning.
ATTENTION:
Install the diaphragm only when the
length of the ø 60/100 coaxial duct is
less than 1 m.
2.8.2
Coaxial duct
accessories
The accessories necessary for the realisa-
tion of this type of discharge and some of
the connecting systems that can be used
are shown in fig. 10.
With the elbow supplied in the kit the
maximum length of the duct should not be
greater than 3 metres.
2.8.3
Positioning the
outlet terminals
The outlet terminals for forced-draught
appliances may be located in the external
perimeter walls of the building.
To provide some indications of possible solu-
tions,
Table 1
gives the minimum distances
to be observed, with reference to the type
of building shown in fig. 11.
2.8.4
Roof outlet
coaxial duct
The roof outlet terminal L.1284 cannot be
shortened and the positioning of the tile
distances must be no less than 600 mm
from the discharge terminal outlet (fig. 12).
The fittings required for this type of dischar-
ge and some of the connecting systems
that can be used are shown in fig. 13.
Up to a maximum of three extensions can
be added to reach a rectilinear length of
3.7 m. If it proves necessary to provide for
78
KEY
1a-b
Coaxial duct kit code 8084802
2
Extension L.815 code 8084800
3
Vertical extension L.584 code 8086900
4
Supplementary 90° elbow code 8085600
TABLE1
Siting of terminal
Appliances from 7 to 35 kW
(distances in mm)
A - below openable window
600
B - below ventilation opening
600
C - below eaves
300
D - below balcony (1)
300
E - from adjacent window
400
F - from adjacent ventilation opening
600
G - from horizontal or vertical soil or drain pipes (2)
300
H - from corner of building
300
I
- from recess in building
300
L - from ground level or other treadable surface
2500
M - between two terminals set vertically
1500
N - between two terminals set horizontally
1000
O - from a surface facing without openings or terminals
2000
P - as above but with openings and terminals
3000
Fig. 11
Fig. 10
1) Terminals below a practicable balcony must be located in such a way that the total
path of the smoke from its outlet point from the terminal to its outlet point from the
external perimeter of the balcony, including the height of possible railings, is not less
than 2000 mm.
2) When siting terminals, where materials that may be subject to the action of the combu-
stion products are present in the vicinity, e.g., eaves, gutters and downspouts painted or
made of plastic material, projecting timberwork, etc., distances of not less than 1500 mm
must be adopted, unless adequate shielding is provided to guard these materials.
Fig. 9
IMPORTANT:
Each additional 90° curve installed reduces the
available length by 0.90 metres.
Each additional 45° curve installed reduces the
available length by 0.45 metres.
