2.15 PERMISSIBLE FLUE LENGTH
The maximum permissible flue lengths for each model is shown in Table A below, these lengths are inclusive of the
terminal resistance.
The value shown is the max available length for extension.
The equivalent length of elbows is shown in Table B.
Table B
Equivalent Length of Elbows (meters)
Concentric
Open Flue
Size
80/125
100/150
80
100
45º
0.85
1.25
0.45
0.60
90º
1.6
1.9
1.0
1.0
Table A
Max Permissible Equivalent Flue Length (inc terminal resistance) meters
Concentric
Open Flue
Flue Size
80/125
100/150
80
100
Model
30/30P
33
-
65
-
40/40P
30
-
70
-
60/60P
17.5
28
25
-
80/80P
10
18
15.3
-
100/100P
-
10
-
20
120/120P
-
9
-
34
150
-
6
-
32
Table D
Maximum lengths
Model
Flue Size
Reduction per Additional Metre
30/30P
80/125mm
0.15% (up to 42m max flue)
40/40P
80/125mm
0.16% (up to 42m max flue)
60/60P
80/125mm
Max flue 17.5m
80/80P
80/125mm
0.5% (up to max 12m max flue)
60/60P
100/150mm
0.18% (up to 30m max flue)
80/80P
100/150mm
0.27% (up to 35m max flue)
100/100P
100/150mm
0.5% (up to 14.3m max flue)
120/120P
100/150mm
0.55% (up to 16.0m max flue)
150
100/150mm
0.8% (up to 7.5m max flue)
Table C
19 Examples of Flue Length Calculation
Example
Max Permissible
Equivalent
Length (Table A)
Elbows
Max permissible
Straight Length
Model
Flue
Type
Type
Equivalent
Length
(Table B)
No
Total
Equivalent
Length
60
80/125
17.5
90
1.6
2
3.2
14.3
60
100/150
28
90
1.9
2
3.8
24.2
80
80/125
10
90
1.6
3
4.8
5.2
120
100/150
9
90
1.9
4
7.6
1.4
Maximum lengths due to the resistance presented by extended concentric flue lengths a slight reduction in the maximum
boiler output
will occur where flue lengths exceed the stated lengths. In such cases the boiler output will be reduced up to
0.8% per additional metre and should not exceed those stated in Table D.
21
Installation & Servicing
SECTION 2 - INSTALLATION
FLUE OUTLET
Summary of Contents for EVOMAX 2 30
Page 4: ...4 Installation Servicing...
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