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8 - INSTALLATION - Vent & combustion air
8.2 - Venting
systems
WARNING!!! The vent installation
must be in accordance with Part
7, Venting of Equipment, of the
latest edition of the National Fuel
Gas Code, ANSI Z223.1/NFPA 54
or section 7, Venting Systems
and Air Supply for Appliances, of
the CAN/CSA B149.1, Natural Gas
and Propane Installation code or
applicable provisions of the local
building codes. Improper venting
can result in excessive levels of
carbon monoxide which can result
in severe personal injury or death!
WARNING!!! Under certain
operating conditions the
temperature of the boiler's fl ue
gases may reach 230°F, (110°C).
Use only the polypropylene vent
piping supplied with the boiler or a
vent system listed by a nationally
recognized testing agency for the
application. Improper venting can
result in excessive levels of carbon
monoxide which can result in
severe personal injury or death!
Horizontal vent runs must be
sloped upwards not less than 1/4
in/ft (21 mm/m), from the boiler to
the vent terminal.
Figure 19 - Relation between Power input and Vent system length
The vent system shall be installed
so as to prevent the accumulation
of condensate. When horizontal
vent runs exceed 5 ft (1.5m), they
must be supported at 3 ft (0.98 m),
intervals with overhead hangers.
Horizontal vent systems shall
terminate at least 4 ft (1.22 m)
below, 4 ft (1.22 m) horizontally
from any door, window or gravity
air inlet into any building. It must
not terminate less than 4 ft (1.22
m) horizontally from, and in no
case above or below, unless a 4
ft (1.22 m), horizontal distance is
maintained, from electric meters,
gas meters, regulators and relief
equipment and not less than 7 ft
(2.3 m) from any adjacent public
walkway. The bottom of the vent
terminal(s) shall be located at least
5 ft (1.5 m) above the air intake
terminal(s). Avoid terminal locations
likely to be affected by winds,
snowdrifts, people and pets. Item
unique to CANADA: vent system
shall terminate at least 6 ft from
electrical and gas meters.
Due to the high effi ciency of the
boiler it may discharge what looks
like white smoke especially when
the outside air temperature is cold.
This is a simply water vapor, a
purely natural phenomenon and not
a reason for concern.
27
The minimum clearance
measurement between two vent
end terminations of this kind of
boilers shall be not less than 18"
(1 m).
WARNING!!! The exhaust vent
and the air inlet lines (also in the
coaxial version) must be supported
to prevent sagging. To do this, use
a suitable pipe clamp to support
the lines. Pipe clamps shall support
the line every 3 ft (1 m). Pipe clamp
shall be fi xed in correspondance
of a wall stud. Improper supporting
can result in excessive levels of
carbon monoxide which can result
in severe personal injury or death!
8.3 - Design of the
venting system
This boiler can be fi tted with a very
long venting system. However there
is a relationship between the length
of the venting system and the power
input of the boiler. Figure 19 shows
this relation which and installer must
consider when in the designing stage
of the venting.
The maximum length of the Split vent
system is 300 ft (Air intake plus fl ue
exhuast).
The maximum length of the concentric
system is 70 ft.
Each 45° elbow inserted in the
concentric or split venting system, has
a loss of pressure equivalent to 2.5 ft
of linear pipe.
Each 90° elbow inserted in the
concentric or split venting system, has
a loss of pressure equivalent to 5 ft of
linear pipe.
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