IBC Technologies SL 30-175, Installation And Operating Istructions, Page: 15 / 78

1-11
INSTALLATION
SL 30-175, SL 45-260 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.
For the
inlet air – 3" or 4” schedule 40 PVC, CPVC, aBs, or PPs piping of any
type is permitted. it is expected that the inlet air be the same size as the exhaust.
NOTE:
it is not permitted to add to the exhaust length by transfer of unused
intake allowance.
Combustion air piping - if used - is inserted directly into the 3” female stainless
steel fitting on the top, right side of the boiler and run horizontally or vertically to
the outdoors. screen material can be placed at the inlet as appropriate for the
environment (e.g. insects, dust).
Care must be taken to ensure adequate separation is maintained between the
air intake inlet and the vent terminal. Refer to the vent terminal configuration
drawings in the Vent termination section above.
support should be provided for intake piping, particularly so for horizontal runs
(follow local code).
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 12: Direct vent combustion air intake
COMBUSTION
AIR FROM
OUTDOORS
“DIRECT VENT”
INSTALLATION
CHECK AIR INTAKE
OUTSIDE TO MAKE
SURE IT IS CLEAR OF
OBSTRUCTIONS
FLUE GAS
EXHAUST TO
OUTDOORS
IBC
SL 30-175
SL 45-260
BOILER
IBC
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.
NOTE
Combustion fan
blockages can occur when
environmental particulate and
foreign matter contaminants
(leaves, dust, dandelion &
cottonwood fluff, etc) are
drawn into the air intake. In
areas where this problem is
suspected to be an issue,
intake air filtration should be
considered. Contact Factory.
Filters should be checked
and cleaned or replaced on
a regular schedule based on
the severity of the problem.
ExHAUST & AIR
INTAKE PIPE SIZE
MAxIMUM EqUIvALENT
LENGTH
3” schedule 40 / rigid PPs (both models) 200' (each side)
4” schedule 40 / rigid PPs (both models) 200’ (each side)
90° long sweep elbow allow 5’ equivalent
90° Vent elbow allow 8’ equivalent
45° elbow allow 3’ equivalent
PPs 87°-90° elbow allow 8’ equivalent
3” PPs Flexible (sl 30-175) 160’ actual; 1.2:1 multiple; 200’ max equiv.
3” PPs Flexible (sl 45-260) 60’ actual; 3.33:1 multiple; 200’ max equiv.
4” PPs Flexible (both models) 160’ actual; 1.2:1 multiple; 200’ max equiv.
Table 4: Exhaust and air intake pipe size