1-11
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.
INTAKE PIPE SIZE
MAxIMUM EqUIVALENT LENGTH
Sched.40; Rigid PPs
2" (15-150 only)
50' (each side)
2-1/2" (15-150 only)
70'
3" (15-150)
120'
3" (45-225)
240'
90° vent elbow
allow 8' equivalent
45° elbow
allow 3’ equivalent
PPs 87-90° elbow
use 8’ equivalent
air intake Filter (Part #103)
allow 8' equivalent
Flexible PPs
2” Flexible
n/a
3” Flexible
60’ maximum (see note 1)
Table 4: Maximum intake piping length
NOTE 1:
Further vent allowance is available for 3” Rigid Single Wall PPs as
follows: VFC 15-150: up to 30’ equivalent; VFC 45-225: up to 60’ equivalent.
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.
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).
Figure 10: Direct vent - intake, exhaust and condensate removal system
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.
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.
Summary of Contents for VFC 15-150
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