LAARS Pennant PNCP - Install and Operating Manual - Manual (Page 10)

LAARS Heating Systems Page 10
OUTDOOR VENT OUTDOOR
SIZE TERMINAL COMBUSTION
AIR TERMINAL
500 20254703 D2007900
750 20254705 D2007900
1000 20254705 D2008000
1250 D2007700 D2008000
1500 D2007700 D2008000
1750 D2007800 D2008000
2000 D2007800 D2008200
Table 6. Vent Terminals for Outdoor Units
Gas Code requires that it be at least 12 inches (30
cm) above grade, but the installer may determine
it should be higher, depending upon local
conditions.
4. If the Pennant is side-wall vented to the same
wall, locate the vent terminal at least 3 feet
(0.9m) horizontally from the combustion air
terminal, and locate the vent terminal at least 1
foot (0.3m) above the combustion air terminal
(see Figure 3).
2.3.3 Vertical Vent Terminal
When the unit is vented through the roof, the
vent must extend at least 3 feet (0.9m) above the point
at which it penetrates the roof. It must extend at least
2 feet (0.6m) higher than any portion of a building
within a horizontal distance of 10 feet (3.0m), and high
enough above the roof line to prevent blockage from
snow. When the combustion air is taken from the roof,
the combustion air must terminate at least 12" (30cm)
below the vent terminal (see Figure 2).
2.3.4 Vertical Combustion Air Terminal
When combustion air is taken from the roof, a
field-supplied rain cap or an elbow arrangement must
be used to prevent entry of rain water (see Figure 2).
The opening on the end of the terminal must be at least
12" (30cm) above the point at which it penetrates the
roof, and high enough above the roof line to prevent
blockage from snow. When the vent terminates on the
roof, the combustion air must terminate at least 12"
(30cm) below the vent terminal.
2.4 Vent Terminals for Outdoor Units
For outdoor applications, the vent and
combustion air openings must be covered with proper
terminals to prevent rain, snow and other objects from
falling into the Pennant.
Part numbers for the terminals to cover the vent
and combustion air openings are shown in Table
6. Vent opening must be on top of the unit, and the
combustion air opening must be on the back of the
unit. The terminals are connected directly to the unit.
No vent piping is used.
Alternately, the installer may use a short piece
of galvanized single wall or B-vent and an approved
rain cap for the vent termination. A minimum 12" of
vent height is acceptable. In addition, a properly sized
single wall galvanized 90° ell can be used for the
intake air terminal, with the open end of the ell facing
down to prevent rain infiltration. The combustion air
inlet opening must still be high enough to prevent
blockage by snow (see Section 2.3.2).