Figure 11
Flue Design
Boiler output in relation to available flue Pa
lower outputs = more Pa and longer flue lengths
0
50
100
150
200
250
300
350
400
450
500
25
26
27
28
29
30
31
32
33
Boiler output ~kW
Available flue ~ Pa
For the purposes of flue design when using the eco hometec PPS 125mm/80mm concentric flue
system then refer to the table below for component resistances.
T
T
a
a
b
b
l
l
e
e
7
7
F
F
l
l
u
u
e
e
R
R
e
e
s
s
i
i
s
s
t
t
a
a
n
n
c
c
e
e
COMPONENT RESISTANCE
80/125 Concentric 500 mm Fanned Flue Kit
80/125 1000mm length PPS/White Galvanised Concentric Flue
80/125 500mm length PPS/White Galvanised Concentric Flue
80/125 PPS/White Galvanised 90
0
elbow
80/125 PPS/White Galvanised 45
0
elbow
80mm 1000mm PPS flue pipe
80mm PPS 90
0
elbow
80mm PPS 45
0
elbow
80/125 Roof Terminal
Open terminal with stainless steel mesh
P.a
5.0
4.5
2.25
4.0
2.0
2.5
1.0
.5
7.5
2.5
For vertical external and internal flues there is a further gain from thermal lift.
This can be calculated from the graph below.
EC 16~38 Installation Manual page
19