Technical data

10
STRATA2
4.3 flue options & terminal position (contd)
PPS Component Resistance Pa For Single Boiler
1m Length DN100 Flue Gas tube 7.0
1m Length DN100 Tube Carrying Air 4.0
90° Bend DN100 Carrying Flue Gas 7.0
90° Bend DN100 Carrying Air 4.0
45° Bend DN100 Carrying Flue Gas 4.0
45° Bend DN100 Carrying Air 2.0
1m Length 100/150 Concentric Tube 12.0
90° 100/150 Concentric Bend 12.0
45° 100/150 Concentric Bend 6.0
100/150 Concentric Terminal
15.0
Vertical or Horizontal
100/100 to 100/150 Concentric Adaptor 2.0
DN100 Open Termination with Bird Mesh 7.0
DN100 Air Tube Termination with Rain Cap 8.0
DN125 Air Tube Termination with Rain Cap 5.0
PPS Component Resistance Pa For Single Boiler
DN150 Air Tube Termination with Rain Cap 2.0
1m Length DN125 Flue Gas tube 2.5
1m Length DN125 Tube Carrying Air 1.5
90° Bend DN125 Carrying Flue Gas 2.5
90° Bend DN125 Carrying Air 1.5
45° Bend DN125 Carrying Flue Gas 1.5
45° Bend DN125 Carrying Air 1.0
DN125 Open Termination with Bird Mesh 2.5
DN150 Open Termination with Bird Mesh 1.0
1m Length DN150 Flue Gas tube 1.0
1m Length DN150 Tube Carrying Air 0.5
90° Bend DN150 Carrying Flue Gas 1.0
90° Bend DN150 Carrying Air 0.5
45° Bend DN150 Carrying Flue Gas 0.5
45° Bend DN150 Carrying Air 0.5
Table 3
examples of calculating flue pressure loss
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
0246810121416182022242628303234363840
B
A
Vertical Flue Lengths - metres
A = Insulated or within the building
B = Uninsulated and exterior to the building
Draught - Pa
example 1
A single Strata 2-120 boiler is to be installed with a
conventional flue arrangement (taking combustion air
from the plantroom) which takes an all vertical internal
route to roof termination using DN100 flue components.
Length of flue = 10m
Resistance =
10 x 1m lengths DN100 tube @ 7.0Pa = 70
1 x DN100 open termination @ 7.0Pa = 7
Total Resistance = 77Pa
Take into account that 10m of internal vertical flue will
generate approximately 33Pa of draught then final
operating resistance is 77 - 33 = 44Pa
conclusion: Operating resistance is less than 100Pa
therefore no alternative design is required as flue system
has no effect on boiler output.
thermal updraught when
flue gas temp 80°C and outside temp -5°C