Equivalent Vent Length Calculation Examples; Standard Sizes Of Boiler Flue Gas Vent Adaptors - Viessmann Vitodens 100-W WB1B Series Installation Instructions Manual

Componentry
Vent Length Requirements

Equivalent vent length calculation examples

* 1
F
D
Fig. 28 Equivalent vent length calculation example
Legend
A Vent termination
B Vent pipe 3.3 ft. (1 m)
C 45º elbow
D Vent pipe 1.6 ft. (0.5 m)
E 87º elbow
F Telescopic extension
*
1
First elbow not included in equivalent vent calculation.
30
(continued)
A
B
C
C
D
D
E
Rigid Venting Systems Installation Instructions
Table 13
Type of fitting
87º elbow/
87º inspection tee
45º elbow
IMPORTANT
Always include vent termination length in calculations.
Equivalent vent length calculation example:
Vitodens 100-W, WB1B 35 and Vitodens 200-W, WB2B 35
(vent system 60/100) (Fig. 28)
2 x 87º elbow........................................3.3 ft. (1 m)
2 x 45º elbow...........................................2 ft. (0.6 m)
3 x vent pipe.........................................4.8 ft. (1.5 m)
1 x vent pipe.........................................3.3 ft. (1 m)
1 x telescopic extension (average length)...1.0 ft. (0.31 m)
1 x vent termination...............................4.2 ft. (1.28 m)
Total equivalent length..........................18.6 ft. (5.67 m)
Table 14 Standard sizes of boiler flue gas vent adaptors
Boiler model
WB1B 26
WB1B 35
WB2B 19
WB1B 26
WB1B 35
WB2B 45
WB2B 60
WB2B 80
WB2B 105
Equivalent length
1.6 ft. (0.5 m)
1 ft. (0.3 m)
*1
Adaptor size
60/100
60/100
60/100
60/100
60/100
80/125
80/125
110/150
110/150