IBC VFC 15-150 Installation And Operating Instructions Manual page 17

WARNING
In addition to preventing
ingestion of chemical
contaminants, care must
be taken to ensure air
intake terminals are not
installed in locations where
contamination might occur
due to ingestion of particulate
foreign material (dust, dirt
and debris).
WARNING
Intake air openings must be
configured such that rain
or other forms of moisture
cannot enter the air intake
piping system. Otherwise
serious damage to the boiler
may result.
NOTE
Care must be taken when
installing air intake piping to
ensure that a "trap" is not
formed in the piping so as to
allow a build-up of water, and
blockage of intake air.
Such blockage will result in a
boiler safety shut-down.
INSTALLATION
VFC 15-150, VFC 45-225 MODULATING GAS BOILERS
1.4.7 "Direct Vent" Combustion Air Intake Piping
There are two basic methods of supplying combustion air to an IBC boiler.
The direct vent option uses piping from the outside to supply combustion air
directly to the boiler's combustion air connection.
Figure 10: Direct vent - intake, exhaust and condensate removal system
INTAKE PIPE SIZE
Sched.40; Rigid PPs
2" (15-150 only)
3" (15-150)
3" (45-225)
90° vent elbow
45° elbow
PPs 87-90° elbow
Air Intake Filter (Part #SC100A)
Flexible PPs
2" Flexible
3" Flexible (VFC 15-150)
3" Flexible (VFC 45-225)
Table 5: Maximum intake piping length
For the inlet air – Schedule 40 PVC, ABS, or PPs piping of any type is permitted.
Use same diameter as Vent pipe, allowing for up to 6 ft actual run of 2" before
any required transition.
NOTE: It is not permitted to add to the exhaust length by transfer of unused
intake allowance.
MAXIMUM EQUIVALENT LENGTH
50' (each side)
120'
240'
allow 8' equivalent
allow 3' equivalent
use 8' equivalent
allow 8' equivalent
N/A
60' (max) actual lineal x 1.5 = equivalent
60' (max) actual lineal x 3 = equivalent
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