Lochinvar EcoForce EF80 Installation, Commissioning, User And Maintenance Instructions page 27

8.6.11 Maximum length – concentric flue
The maximum length of the flue system is determined by the resistance of the components within the flue.
The resistance must not exceed 200 Pa.
The information shown in table 8.6.12 is for the Lochinvar supplied flue system only; other flue system suppliers
may have different values.
Wall terminal
Roof terminal
Straight tube (m)
45° Elbow
90° Elbow
8.6.12 Concentric flue component resistances (pa)
8.6.13 Worked example – concentric flue
100/150mm Concentric flue
Item
Wall terminal
Roof terminal
Straight tube (m)
45° Elbow
90° Elbow
Item
Wall terminal
Roof terminal
Straight tube (m)
45° Elbow
90° Elbow
EF80 EF100
(80/125) (100/150)
22 19
61 39
12 8
7 8
13 11
Flue Resistance Calculation Example
EXAMPLE A
EF100 WATER HEATER WITH HORIZONTAL CONCENTRIC TERMINAL
3000mm VERTICAL FLUE LENGTH
6000mm HORIZONTAL FLUE LENGTH
90° BEND
EXAMPLE B
EF150 WATER HEATER WITH HORIZONTAL CONCENTRIC TERMINAL
3000mm VERTICAL FLUE LENGTH
600mm HORIZONTAL FLUE LENGTH
90° BEND
Example A
Quantity
1
0
9
0
1
Example B
Quantity
1
0
9
0
1
228>200 FLUE SYSTEM DESIGN HAS FAILED USE TWIN PIPE OR CONVENTIONAL FLUE INSTEAD
EF120 EF150
(100/150) (100/150)
24 40
45 69
10 14
9 14
13 22
Resistance
19
39
8
8
11
Total Resistance (Pa)
141<200 FLUE SYSTEM DESIGN HAS PASSED
Resistance
40
69
14
14
22
Total Resistance (Pa)
EF180
(100/150)
48
86
16
16
28
Total
19
0
72
0
11
141
Total
40
0
126
0
22
228
27