Vent Length Requirements; Maximum Allowable Equivalent Length - Horizontal - Viessmann Vitodens 100-W WB1B Series Installation Instructions Manual

Rigid Venting Systems Installation Instructions

Vent Length Requirements

Maximum vent/air intake pipe length - horizontal
IMPORTANT
Always include vent termination length in calculations.
Table 24 Maximum allowable equivalent length - horizontal
Boiler Model System Ø See note below
WB1B 26, 35
g
WB2B 19, 26, 35
g
WB2B 45, 60
g
WB2B 80, 105
g
* 2 in. to 3 in. or 2 in. to 4 in. increaser field supplied.
1
* 2 See figure 50 and 51.
Note: For combination of different vent/air intake pipe diameters, such as Ø 3 in. stainless steel vent with Ø 2 in.
(CVPC, PVC, ABS) air intake pipe, the total equivalent length must be used for the smaller pipe diameter.
Minimum vent length is 3.3 ft. (1 m).
Fig. 50 Vitodens 100-W and 200-W WB2B 19, 26, 35
IMPORTANT
For PP(s) systems, all exhaust vent and air intake piping
and elbows exposed outside, must be UV resistant
polypropylene (supplied by the vent manufacturer).
2 in. (51 mm)
3 in. (76 mm
4 in. (102 mm)*
1
2 in. (51 mm)
3 in. (76 mm)* 1
4 in. (102 mm)* 1
3 in. (76 mm)
4 in. (102 mm)* 1
4 in. (102 mm)
A
Flue starter adaptor
Air intake starter adaptor
Boiler vent pipe adaptor
For PP(s) see page 49.
Direct Venting (Two-pipe System)
The total equivalent length specified for a two pipe system
is the total combined length of the exhaust vent and air
intake pipe system.
Do not exceed these maximum lengths.
See table 24 and fig. 50 and 51 for reference.
All PP(s) vent material and air intake (if PP(s) used) must
be ULC S636 or UL1738 listed, manufactured by M&G
(Muelink & Grol b.v.) / DuraVent, or Centrotherm.
Max. combined equivalent vent length (a+b)*
86 ft. (31 )
164 ft. (50 m)
200 ft. (61 m)
115 ft. (35 m)
148 ft. (45 m)
180 ft. (55 m)
98 ft. (30 m)
148 ft. (45 m)
131 ft. (40 m)
a
b
Legend
A Support system
B Exhaust pipe termination with screen
C Combustion air intake with screen
a Equivalent vent length (exhaust)
b Equivalent vent length (air intake)
2
Side wall
Caulk here
(Exterior caulking)
B
Flue
C
Air
51