76
the requirements of the current stan-
dards, as well as the following practical
pointers:
–With direct intake from outside, when
the pipe is longer than 1 m, you are
recommended to insulate the piping so
as to prevent formation of dew on the
outside of the piping during particularly
hard periods of the year.
– With the outlet pipe outside the buil-
ding or in cold indoor environments,
insulation is necessary to prevent bur-
ner failure in starting.
In such cases, provide for a condensa-
te-collector system on the piping.
– If a segment of the flue passes through
a flammable wall, this segment must be
insulated with a glass wool pipe insula-
tor 30 mm thick, with a density of 50
kg/m
3
.
The maximum overall length of the
intake and exhaust ducts depends on
the head losses of the single fittings
installed (excluding the doublers) and
must not be greater than 7.50 mm H
2
O
vers. “25 BF” e 11 mm H
2
O VERS. “30
BF”.
For head losses in the fittings, refer to
Table 1
.
2.8.1
Separate
flue kit
(fig. 8)
The separate flue kit code 8089904 is
supplied with an intake diaphragm which
must be used as shown in fig. 8/a, depen-
ding on the maximum load loss permitted
in both flues.
TABLE 1
Accessories ø 80
Load loss (mm H
2
O)
25 BF
30 BF
Intake
Outlet
Roof out. Intake
Release
Outlet Roof out.Intake
90° curve MF
0,30
0,40
–0,30
0,50
–
45° curve MF
0,20
0,30
–0,20
0,40
–
Extension L. 1000 (horizontal)
0,20
0,30
–0,20
0,40
–
Extension L. 1000 (vertical)
0,30
0,20
–0,30
0,30
–
Outlet terminal
–0,30
–
– 0,40
–
Intake terminal
0,10
––
0,10
–
–
Manifold
0,50
1,60
–0,50
1,80
–
Roof outlet terminal L.1240
––
0,50
– –0,60
Condensation collection T
–1,00
–
– 1,10
–
1
2
3
4
6
165
110
165
K
ø 80
ø 80
100
92
Fig. 8
KEY
1 ø125/95 sponge seal
2 Fixing screw
3 Flue outlet flange
4 Inlet air diaphragm
6 Manifold with intakes
25 BF
30 BF
K mm
180
205
Fig. 8/a
Model “30 BF”
N° segments
Total load loss
to remove
mm H
2
O
Pa
n° 1
0 ÷ 1
0 ÷ 9,8
n° 1 e 2
1 ÷ 2
9,8 ÷ 19,6
da n° 1 a 4
2 ÷ 3
19,6 ÷ 29,4
da n° 1 a 5
3 ÷ 4
29,4 ÷ 39,2
da n° 1 a 7
4 ÷ 5
39,2 ÷ 49,0
da n° 1 a 8
5 ÷ 6
49,0 ÷ 58,8
da n° 1 a 10
6 ÷ 7
58,8 ÷ 68,6
without diaphragm
7 ÷ 7,5
68,6 ÷ 73,5
Model “25 BF”
N° segments
Total load loss
to remove
mm H
2
O
Pa
none
0 ÷ 1
0 ÷ 9,8
n° 1
1 ÷ 2
9,8 ÷ 19,6
n° 1 e 2
2 ÷ 3
19,6 ÷ 29,4
da n° 1 a 3
3 ÷ 4
29,4 ÷ 39,2
da n° 1 a 4
4 ÷ 5
39,2 ÷ 49,0
da n° 1 a 5
5 ÷ 6
49,0 ÷ 58,8
da n° 1 a 6
6 ÷ 7
58,8 ÷ 68,6
da n° 1 a 7
7 ÷ 8
68,6 ÷ 78,4
da n° 1 a 8
8 ÷ 9
78,4 ÷ 88,2
da n° 1 a 9
9 ÷ 10
88,2 ÷ 98,0
without diaphragm
10 ÷ 11
98,0 ÷ 107,8
Example of allowable installation calculation in that the sum of the head losses of the single fit-
tings is less than 7.50 mm H
2
O
Intake
Outlet
7 meter horizontal pipe ø 80 x 0.20
1.40
–
7 meter vertical pipe ø 80 x 0.30
–2.10
n° 2 90° elbows ø 80 x 0.30
0.60
–
n° 2 90° elbows ø 80 x 0.40
–0.80
N° 1 terminal ø 80
0.10
0.30
Total head loss
2.10
+
3.20
=
5
.
3 mm H2O
With this total head loss, remove the segments from n. 1 to n. 8
from diaphragm in the intake pipe.
