LAARS Mascot LX MLXC 175 MBH - Install and Operating Manual - Manual (Page 14)

LAARS Heating Systems Page 10
3.2 Venting (Exhaust)
The flue temperature of the Mascot LX changes
dramatically with changes in operating water
temperature. Therefore, it is necessary to assess the
application of the boiler to determine the required
certified vent class. If the Mascot LX is installed in
an application where the ambient temperature is
elevated, and/or installed in a closet/alcove, CPVC,
polypropylene, or stainless steel material is required.
If the system temperatures are unknown at the time
of installation, stainless, polypropylene or CPVC
material is recommended.
The Mascot LX is a Category IV appliance and may
be installed with PVC, CPVC or polypropylene that
complies with ULC-S636, ANSI/ASTM D1785 F441
(see Table 4) or a stainless steel venting system that
complies with UL 1738 Standard (see Table 8 ).
WARNING
Failure to use the appropriate vent material, installation
techniques, glues/sealants could lead to vent failure
causing property damage, personal injury or death.
have a minimum free area of 1 square inch per 3000
Btu/hr (734 square mm/kW) of the total input rating of
all equipment located in the enclosure. This opening
must not be less than the sum of the areas of all vent
connectors in the confined space.
Other methods of introducing combustion and
ventilation air are acceptable, providing they conform to
the requirements in the applicable codes listed above.
In Canada, consult local building and safety codes or, in
absence of such requirements, follow CAN/CGA B149.
3.1.2 Ducted Combustion Air
The combustion air can be taken through the wall, or
through the roof. When taken from the wall, it must
be taken from out-of-doors by means of the LAARS
horizontal wall terminal, shown in Table 5 . See Table 4
to select the appropriate diameter air pipe. When taken
from the roof, a field-supplied rain cap or an elbow
arrangement must be used to prevent entry of rain water
(see Figure 5 ).
Use ABS, PVC, CPVC, polypropylene, or galvanized
pipe for the combustion air intake (see Table 6 ), sized
per Table 4 . Route the intake to the boiler as directly
as possible. Seal all joints. Provide adequate hangers.
The unit must not support the weight of the combustion
air intake pipe. Maximum linear pipe length allowed is
shown in Table 4 . Subtract 5 allowable linear ft. (1.5m)
for every elbow used.
The connection for the intake air pipe is at the top of the
unit (see Figure 3 ).
In addition to air needed for combustion, air shall also
be supplied for ventilation, including air required for
comfort and proper working conditions for personnel.
Table 5. Vent Termination Options
Part Number Size Description
239-44069-02 2" PVC Concentric Vent Terminal
239-44069-01 3" PVC Concentric Vent Terminal
CA010101 2" Flush Vent Terminal PVC
CA010100 3" Flush Vent Terminal PVC
CA007100 3" to 5" Stainless Steel Concentric Vent Terminal
INSTALLATION STANDARDS
MATERIAL UNITED STATES CANADA
ABS ANSI/ASTM D1527
PVC, sch 40 ANSI/ASTM D1785 or D2665 Air pipe material must be chosen
CPVC, sch 40 ANSI/ASTM F441 CPVC, sch 40, ANSI/ASTM, Polypropylene
Polypropylene UL1738, ULC S636. based upon the intended application of the boiler.
Single wall galv. steel 26 gauge
Table 6. Required Combustion Air Pipe Material.