Maximum Vent/Air Intake Pipe Length - Stainless Steel System With Plastic Air Intake Pipe - Viessmann Vitodens 100-W WB1A-24 Installation Instructions Manual

Vent Length Requirements
Maximum equivalent vent length - stainless steel system with plastic air intake pipe
Note:
For system venting layout
see fig. 48.
IMPORTANT
First elbow not included in equivalent
vent calculation.
Always include vent termination length
in calculations.
Table 39. (see also fig. 47)
Vent type
Exhaust vent pipe
Air intake pipe
Equivalent vent length calculation example
(Vitodens 200-W, WB2 11-44, system diameter 4")
Maximum allowable equivalent length is 52 ft. / 16 m
(see table 35. on page 51)
2 x 90º stainless steel elbow
2 x 45º stainless steel elbow
Air intake pipe
1 x 90º plastic (ABS/CPVC/PVC) elbow
1 x 45º plastic (ABS/CPVC/PVC) elbow
Exhaust vent pipe
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air intake pipe
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Combined total equivalent vent length
(a+b)
Direct Venting (Two-pipe System)
Type of fitting
90° elbow
(stainless steel)
45° elbow
(stainless steel)
90° elbow
(ABS/PVC)
45° elbow
(ABS/PVC)
6 ft./1.83 m
. . . . . . . . . . . . . . . . . . . . . . . . . . .
4 ft./1.22 m
. . . . . . . . . . . . . . . . . . . . . . . . . . .
5 ft./1.52 m
. . . . . .
3 ft./0.91 m
. . . . . .
10 ft./3.05 m
10 ft./3.05 m
38 ft./11.58 m
Equivalent
length
ft. / m
3 / 0.91
2 / 0.61
5 / 1.52
3 / 0.91
55