LAARS MagnaTherm MGV - Installation, Operation and Maintenance Instructions - Manual (Page 13)

MagnaTherm Boilers and Water Heaters Page 9
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/
CSA B149.
3.1.2 Ducted Combustion Air
The combustion air can be taken through the wall, or
through the roof. LAARS offers accessories to use
with ducted air systems, as shown in Table 3.
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 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
equivalent pipe length allowed is 100 feet (30 m).
Each elbow is considered to be 5 feet (1.5m)
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
applications, two elbows must be installed on the
end of the inlet to act as a vent terminal. When
elbows are use as terminals, appropriate screens
must be installed to prevent blockage.
The elbow(s) required for termination are not
included in the kits sown in Table 3
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. Refer to the applicable codes.
3.2 Venting
WARNING
Selection of improper vent materials for
installations that are installed in closets, or will be
operated in high ambient temperature levels, may
lead to property damage, personal injury, or death.
WARNING
Failure to use the appropriate vent material,
installation techniques, or glues and sealants
could lead to vent failure causing property
damage, personal injury or death.
WARNING
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.