INSTALLATION AND OPERATION INSTRUCTIONS
1-12
SL 20-115 MODULATING GAS BOILER
INTAKE PIPE SIZE
MAxIMUM EqUIvALENT LENGTH
Sched.40; Rigid PPs
2”
100’
3”
240’
90° long sweep elbow
allow 5’ equivalent
90° vent elbow
allow 8’ equivalent
45° elbow
allow 3’ equivalent
PPs 87-90° elbows
use 8’ equivalent
air intake Filter (Part #103)
allow 8’ equivalent
Flexible PPs
2” Flexible
45’ (max.) lineal x 1.4 = equivalent
3” Flexible
98’ (max.) lineal x 1.2 = equivalent
Table 4: Maximum intake piping length
For the
inlet
air – schedule 40 PVC, CPVC, aBs or PPs piping of any type is
permitted. use same diameter as Vent pipe.
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).
1.4.8 “Indoor Air” Combustion Air Intake
WARNING
When using Indoor
Air options, adequate
combustion air must be
supplied to the boiler room
according to the requirements
of all applicable codes.
Figure 13: Indoor combustion air intake