LAARS Heating Systems
Page 8
Method 2
: One permanent opening, commencing
within 12” (300 mm) of the top of the enclosure,
shall be permitted. The opening shall directly
communicate with the outdoors or shall
communicate through a vertical or horizontal duct
to the outdoors or spaces that directly communicate
with the outdoors and shall 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 3a. 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 Fig. 6).
Use ABS, PVC, CPVC, polypropylene, stainless
steel, or galvanized pipe for the combustion air
intake. (See Table 4.) The intake must 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. The maximum linear
pipe length allowed is 100 feet (39 m). Subtract 5
allowable linear ft. (1.5 m) for every elbow used.
When using polypropylene or stainless steel
materials in horizontal duct configurations, a single
elbow must be installed on the end of the air inlet
to act as an outdoor terminal. In vertical duct
fig. 6 - Combustion air and Vent through roof
table 5 - required exhaust Vent material
Installation Standards
Material
United States
Canada
Stainless steel
UL 1738
Venting must be ULC-S636 certified for use as
venting material. The venting material must be
chosen based upon the intended application of the
boiler, and must be installed according to the vent
manufacturer’s instructions.
PVC*, sch 40
ANSI/ASTM D178
CPVC, sch 40
ANSI/ASTM F441
Polypropylene
UL-S636 Class 2C
* PVC cannot be used for the first 12 inches of vent material
applications, two elbows must be installed on the
end of the inlet to act as a vent terminal. In both
installation types, Laars part number CA008500 can
then be installed into the elbow to prevent foreign
objects from entering the air inlet system. The
elbow(s) required to complete the vent terminal is
not included.
The connection for the intake air pipe is on the back
panel.
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.
Summary of Contents for NTV1000
Page 2: ......
Page 35: ...NeoTherm Boilers and Water Heaters Page 31 Fig 20 Ladder Diagram...
Page 36: ...LAARS Heating Systems Page 32 Fig 21 Wiring Diagram...
Page 37: ...NeoTherm Boilers and Water Heaters Page 33...
Page 51: ...NeoTherm Boilers and Water Heaters Page 47 Fig 52 Connection Terminals...
Page 130: ...LAARS Heating Systems Page 126 Fig 140 Machine Frame and Rear Panel 13 3 PARTS ILLUSTRATIONS...
Page 131: ...NeoTherm Boilers and Water Heaters Page 127 Fig 141 Front Panel and Covers...
Page 132: ...LAARS Heating Systems Page 128 Fig 142 Burners and Combustion Chambers...
Page 134: ...LAARS Heating Systems Page 130 Fig 145 Electronic Components...
Page 135: ...NeoTherm Boilers and Water Heaters Page 131 Fig 146 Condensate Trap Fig 147 Control Bezel...
Page 136: ...LAARS Heating Systems Page 132 Fig 148 Flow Switch...
Page 137: ...NeoTherm Boilers and Water Heaters Page 133 This page intentionally left blank...
