Vent And Combustion Air Pipe Lengths - Bosch ZBR16-3A Series Installation And Service Instructions Manual

44 | Installation
X
Y
1
Fig. 39 Vertical venting system (sealed combustion)
[1] Intake
[2] Exhaust
X Greater than 12 inches (305 mm)
Y 12 inches (305 mm) above maximum snow level or at least
24 inches (610 mm) whichever is greater
1 2
Fig. 40 PolyPro Flex Chimney Cap (PP) vertical venting system (sealed
combustion)
[1] Intake
[2] Exhaust
6 720 806 992 (2015/03)
X
2
6 720 641 933-08.1O
6 720 806 922-08.2O
X
Y
Fig. 41 Horizontal venting system (telescopic concentric vent kit)

6.8.3 Vent and combustion air pipe lengths

With Flex Pipe the maximum length is reduced by 50%.
Flex Pipe according to the suppliers instructions for use
in the vertical part of the installation only.
3" (76 mm) Vent and combustion air pipe
For all installation situations and for all appliances the maximum vent
and combustion air pipe length is 100 feet each, with no more than
8 elbows each.
2" (50 mm) Vent and combustion air pipe
The maximum combined vent and combustion air pipe length
( tab. 20, 21 and 22) depend on the installation situation, the
appliance type and the number of elbows used.
Installations  Fig. 32, 33, 34, 36, 37 and 39
Separate terminations
2" PIPE
Number of 90 °
elbows used
1
2
3
4
5
6
Table 20 Vent and combustion air pipe lengths with 2" diameter and
separate terminations
1/4" per foot
(50 mm per meter)
Maximum straight vent pipe length allowed
for Ø 2" pipe
ZBR16-3A ZBR35-3A
ZBR21-3A ZWB35-3A
ZBR28-3A ZBR42-3A
ZWB28-3A ZWB42-3A
81 ft (24.6 m) 65 ft (19.8 m)
76 ft (23.1 m) 57 ft (17.3 m)
71 ft (21.6 m) 48 ft (14.6 m)
66 ft (20.1 m) 40 ft (12.2 m)
61 ft (18.6 m) 32 ft (9.8 m)
56 ft (17.1 m) 23 ft (7.0 m)
6 720 641 933-78.1O
Greenstar