Direct vent installations (sealed combustion)
For direct vent applications all applicable items below must be met.
1
X
Fig. 30 Vent and combustion air pipe position of a sealed combustion
system
[1]
Intake
[2]
Exhaust
X
At least 1 foot (305 mm)
The termination shall terminate at least 1 foot (305 mm) below, 1 foot
(305 mm) horizontally from or 1 foot (305 mm) above any door,
window or gravity air inlet into any building ( fig. 31 [2], [X
page 41).
If multiple boilers are installed in a row, allow at least 1 foot (305 mm)
clearance between the vent termination of one and the combustion air
intake of the other.
Material
PVC schedule 40, 80
2" (50 mm) Vent or
air pipe and fitting
PVC-DWV
CPVC schedule 40, 80
PVC schedule 40, 80
3" (76 mm) Vent or
air pipe and fitting
PVC-DWV
CPVC schedule 40, 80
PP rigid venting
3" (80 mm) vent or
air pipe M&G
Duravent PolyPro and
Centrotherm
PP rigid venting
2" (50 mm) vent or
air pipe M&G
Duravent PolyPro and
Centrotherm
PP rigid venting
3"/5" (80/125 mm)
concentric (Bosch,
manufactured by
PP rigid venting
M&G Duravent)
Table 17 Materials for pipe
Greenstar
2
X
6 720 641 933-19.1O
], [X
1
Item
United states
ANSI/ASTM D1785
ANSI/ASTM D2665
ANSI/ASTM F441
ANSI/ASTM D1785
ANSI/ASTM D2665
ANSI/ASTM F441
ANSI Cat IV
Approved Polypropylene
InnoFlue
ANSI Cat IV
Approved Polypropylene
InnoFlue
ANSI Cat IV
Approved Polypropylene
ANSI Cat IV
Approved Polypropylene
Vent termination must be at least 1 foot (305 mm) above grade,
anticipated snow line or roof surface (Canada
1-1/2 feet (457 mm) minimum) ( fig. 31 [Y
Vent termination must be at least 7 feet (2135 mm) above a public
walkway ( fig. 31 [X
from the termination does not create a hazard or a nuisance.
Vent termination must be 3 feet (915 mm) above any forced air intake
within 10 feet (3 050 mm) ( fig. 31 [1], [Y
Do not extend exposed vent pipe outside the building beyond
recommended distance. Condensate could freeze and block vent pipe.
Vent should terminate at least 3 feet (915 mm) away from adjacent
walls, inside corners and 5 feet (1 525 mm) below roof overhang
( fig. 31 [X
], [X
], page 41).
2
4
It is not recommended to terminate vent above any door or window,
condensate can freeze causing ice formations.
Do not use chimney as a raceway if another boiler or fireplace is vented
into or through chimney.
All PVC/CPVC vent pipes must be glued, except for the flue gas adapter-
pipe connection.
The exhaust pipe must be properly supported and
pitched a minimum of ¼ inch (6.35 mm) per foot back to
the boiler. This allows the condensate to properly drain.
NOTICE: Damage of 2 inch PVC pipes.
▶ For ZBR42-3A and ZWB42-3A use 2 inch CPVC-pipes
or 3 inch pipes.
],
3
All PP/PVC/CPVC combustion air and vent pipe materials and fittings
must comply with the following and must be UL approved venting
material:
Canada
BH Gas venting systems,
1)
ULC S636
Class IIA - PVC,
Class IIB - CPVC,
Class IIC - Polypropylene
(certified to ULC S636)
Installation | 39
], page 41).
A
], page 41). Ensure that condensate spilling
5
], page 41).
B
X
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6 720 806 992 (2015/03)
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