Maximum Vent/Air Intake Pipe Length - Vertical / Horizontal (Hybrid System) - Viessmann Vitodens 100-W WB1A-24 Installation Instructions Manual

Vent Length Requirements
Maximum vent/air intake pipe length - horizontal/vertical (hybrid system)
Table 37. Maximum allowable equivalent length - vertical
exhaust / horizontal air intake (hybrid)
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 system. See Fig. 47.
Minimum vent length is 3.3 ft. / 1m.
Flue
c
Support
system
a
Support
system
Fig. 46
(continued)
System Ø Max. combined
vent length (a+b)
3" / 76mm
*
4" / 102mm
3" / 76mm
4" / 102mm
3" / 76mm
4" / 102mm
4" / 102mm
(for larger Ø system
consult Viessmann)
4" / 102mm
(for larger Ø system
consult Viessmann)
Support
system
b
Direct Venting (Two-pipe System)
equivalent
59ft. / 18m
72ft. / 22m
59ft. / 18m
71ft. / 21.6m
44ft. / 13.5m
57ft. / 17.1m
59ft. / 18m
44ft. / 13.5m
Air
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 37., as well as Figs. 44, 45, and
46 for reference.
Legend
Support system
Flashings
Exhaust (straight coupling) with
screen
Combustion air intake with screen
a Equivalent length (exhaust)
b Equivalent length (air intake)
c min. 18" / max. 48"
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