LAARS NeoTherm NTV (Sizes 150–850 MBTU/h) - Install and Operating Manual - Manual (Page 14)

Page 10 LAARS Heating Systems
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/CSA B149.
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 3a and 3b. See Table 2 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 Figure10.)
Use ABS, PVC, CPVC or galvanized pipe for the combustion
air intake. (See Table 4.) The pipe should be sized per Table
2. 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 2. 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 9.)
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. Refer to the
applicable codes.
3.2 Venting
WARNING
Failure to use polypropylene CPVC or stainless steel
venting for the first 20” (285-600) / 30” (80-210) of vent
material or for any part of the venting that is installed
inside a closet may lead to property damage, personal
injury or death. The proper length of this material is
supplied with boiler. Boilers in the U.S. may use pipe
included with the boiler.
Failure to use the appropriate vent material, installation
techniques, glues/sealants could lead to vent failure
causing property damage, personal injury or death.
All venting must be installed according to this manual
and any other applicable local codes, including but
not limited to, ANSI Z223.1/NFPA 54, CSA B149.1,
CSAB149.2 and ULC-S636. Failure to follow this manual
and applicable codes may lead to property damage,
severe injury, or death.
The flue temperature of the NeoTherm 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 NeoTherm is installed in an
application where the ambient temperature is elevated,
and/or installed in a closet/alcove, polypropylene, CPVC
or stainless steel material is required. If the system
temperatures are unknown at the time of installation,
Class IIB or higher venting material is recommended.
The NeoTherm is a Category IV appliance and may be
installed with PVC and CPVC that complies with ANSI/
ASTM D1785 F441, polypropylene that complies with
ULC-S636 Class IIb, or a stainless steel venting system that
complies with UL 1738 Standard. (See Table 5.)
The unit’s vent can terminate through the roof, or through an
outside wall.
When using PVC/CPVC for vent material, venting must be
connected to the CPVC section included with NeoTherm sizes
80-850. The CPVC vent section included with the NeoTherm
may be broken by CPVC fittings if necessary, but never
reduced in total length. See Table 2 to select the appropriate
vent pipe diameter. When using polypropylene, all vent
material must be produced by the same manufacturer, and
have a ULC-S636 rating.
Figure 10 - Combustion Air and Vent Through Roof
INSTALLATION STANDARDS
MATERIAL UNITED STATES CANADA
Stainless Steel UL 1738 Venting must be ULC-S636 certified for use as
PVC, sch 40 ANSI/ASTM D1785 venting material. The venting material class must be
CPVC, sch 40 ANSI/ASTM F441 chosen based upon the maximum flue gas temperature
Polypropylene ULC-S636 and the intended application of the boiler.
Table 5 - Required Exhaust Vent Material
*
*
*
*
*
*
*
In Canada, refer to CAN/CSA B199.1