Vent Length Requirements; Maximum Vent/Air Intake Pipe Length - Horizontal - Viessmann Vitodens 100-W WB1A-24 Installation Instructions Manual

Vent Length Requirements

Maximum vent/air intake pipe length - horizontal

Table 35. Maximum allowable equivalent length - horizontal
Boiler Model
HWB1A 8-24, 8-30
HWB2 6-24C, 6-24
HWB2 8-32
HWB2 11-44
HWB2 15-60
*
4" (3" to 4" increaser field supplied. Do not order Viessmann 4" parallel adaptor).
Maximum of five 90° elbows allowed in the entire vent and air intake systems
(first 90º elbows are not included). See Fig. 47
Minimum vent length is 3.3 ft. / 1m.
Field Supplied
Exhaust/Air Intake
Pipe and Fittings
Vitodens Boiler
Fig. 44
Legend
Support system
Exhaust pipe termination with
screen
Combustion air intake with screen
a Equivalent vent length (exhaust)
b Equivalent vent length (air intake)
System Ø Max. combined
vent length (a+b)
3" / 76mm
*
4" / 102mm
3" / 76mm
4" / 102mm
3" / 76mm
4" / 102mm
4" / 102mm
4" / 102mm
Starter Adaptor
Parallel Adaptor
Boiler Adaptor
Direct Venting (Two-pipe System)
equivalent
52ft. / 16m
66ft. / 20m
52ft. / 16m
63ft. / 19.2m
40ft. / 12m
50ft. / 15.2m
52ft. / 16m
40ft. / 12m
a
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 lenghts. See
table 35., as well as Figs. 44, 45, and
46 for reference.
IMPORTANT
First elbow not included in equivalent
vent calculation.
Always include vent termination length
in calculations.
Side Wall
Caulk here
(exterior caulking)
b
Flue
Air
51