
E n e r g y T e c h n o l o g y
Ltd.
17
14.0 calculating
flue resistance
The excess pressure available for overcoming the frictional resistance of a flue system is 100 Pa. The adjacent table
of flue component resistances will assist the designer in calculating total flue system frictional loss.
If the total installed flue system resistance exceeds 100 Pa., then the result will be a reduction in boiler output.
Reference to the ‘Effect of Flue System Resistance On Boiler Output”, graphs will assist. If the resistance of a
proposed flue system has an unacceptable effect on boiler output, then a larger diameter flue tube should be
selected.
Thermal up-draught is generated in a vertical flue system, reducing the resistance of the system. Reference to the
“Thermal Up-draught Graph’ will provide a figure in Pa., which may be deducted from the total calculated flue system
resistance.
NB. Thermal up-draught does not apply to horizontal sections of a flue system.
COMPONENT RESISTANCE (Pa)
45
62
76
70/125 Concentric Wall Terminal
14.6
21.4
31.2
70/125 Concentric Roof Terminal Without Rain Cap
14.6
21.4
31.2
70/ 125 Concentric Roof Terminal With Rain Cap
21.9
32.2
46.8
1m length 70/125 Concentric Tube
10.7
16.6
23.4
93
°
C 70/125 Concentric Bend
10.7
16.6
23.4
45
°
C 70/125 Concentric Bend
5.4
8.3
11.7
1m length DN 70 PPS Tube Carrying Fluegas
9.7
14.6
21.4
1m length DN 70 PPS Tube Carrying Combustion Air
5.8
9.7
13.6
90
°
DN 70 PPS Bend Carrying Fluegas
9.7
14.6
21.4
90
°
DN 70 PPS Bend Carrying Combustion Air
5.8
9.7
13.6
45
°
DN 70 PPS Bend Carrying Fluegas
4.9
7.8
10.7
45
°
DN 70 PPS Bend Carrying Combustion Air
2.9
4.9
6.8
Room Sealed Chimney Cap DN 70
13.6
19.5
29.2
DN 70 x 100 PPS Increaser Piece-Fluegas or Air
1.9
1.9
1.9
90
°
DN 100 PPS Bend Carrying Fluegas
3.9
4.9
7.8
90
°
DN 100 PPS Bend Carrying Combustion Air
2.9
2.9
3.9
45
°
DN 100 PPS Bend Carrying Fluegas
1.9
2.5
3.9
45
°
DN 100 PPS Bend Carrying Combustion Air
1.6
1.9
1.9
Im length DN 100 PPS Tube Carrying Fluegas
2.0
2.5
4.0
Im length DN 100 PPS Tube Carrying Combustion Air
1.5
2.0
2.0
DN 70 Open Termination With Mesh
7.8
10.7
15.6
DN 100 Open Termination with Mesh
2.0
3.0
4.0
70/125 To 100/150 Concentric Increaser
3.9
5.8
9.7
90
°
DN 100 PPS Bend Carrying Fluegas
2.0
2.5
4.0
90
°
DN 100 PPS Bend Carrying Combustion Air
1.5
2.0
2.0
45
°
DN 100 PPS Bend Carrying Flue gas
1.0
1.3
2.0
45
°
DN 100 PPS Bend Carrying Combustion Air
0.8
1.0
1.0
1m length DN 100 PPS Tube Carrying Flue gas
2.0
2.5
4.0
Summary of Contents for MICROMAT EC 45
Page 1: ......
Page 2: ......
Page 43: ...43 18 2 dipswitch settings E n e r g y T e c h n o l o g y Ltd ...
Page 46: ...46 18 4 setting weather compensation E n e r g y T e c h n o l o g y Ltd ...
Page 47: ...47 18 4 setting weather compensation E n e r g y T e c h n o l o g y Ltd ...
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