IBC Technologies Inc.
7
VFC 15-150 and VFC 45-225
supply water temperatures up to 185°F.
While IBC’s stack temperatures are
generally within 5°F of the return water
temperature – even at full throttle, the
higher return water temperatures
associated with a 185°F supply call for
CPVC vent material. However, using
IBC’s CoolVent™ option – with a
supplemental 145°F vent limit switch
located at the base of the heat exchanger,
the stack temperature at the vent
connection will be below 149°F (see
Technical Memo 07-01).
For long vent runs with higher initial
exhaust temperature, consider use of
mixed materials for economy: CPVC for
the initial run followed by PVC to the
termination. Ensure appropriate
transition glue is used. The installer is
responsible to ensure that sufficient
temperature loss is allowed for in the
CPVC section to fall below the limit for
PVC, taking into account the highest
possible ambient temperature in the area
of vent travel (e.g. boiler room, attic
and/or chase). Watch for further
guidance on materials combinations:
IBC will publish and update Technical
Memo 07-01 on the subject as product
configurations and
ULC-S636
inspection
practices evolve.
•
USA:
PVC (Sch. 40 ASTM D1785 or
D2665 and fittings) or CPVC (Sch.
40/ASTM F441 with Sch. 80 fittings); or
CSA approved 3" stainless vent systems.
For the
inlet
air – PVC, CPVC or ABS (all
Sch.40) are permitted.
Do not use ABS or any cellular core pipe for
exhaust venting.
The boiler offers 2” venting connections.
Fittings are to be used to adapt to the
appropriate diameter – see
Vent Travel
below. Exhaust venting is to be connected
directly to the 2” NPT male threaded
stainless steel fitting on the bottom of the
pressure vessel using a 2" PVC or CPVC
threaded adaptor or 90° elbow adaptor. A
condensate trap formed using the supplied
fittings shall be spliced into the exhaust or
near the base of the boiler. See Figure 2.
Combustion air piping is connected at the
base of the boiler using a standard 2" PVC
(ABS) coupler or elbow. Screen material can
be placed at the inlet as appropriate for the
environment (e.g. insects, dust).
Venting shall be supported in accordance
with applicable code.
1.4.1.2
Vent Travel
3” CPVC or PVC (Canada:
ULC-S636
approved; USA: solid DWV) piping is the
standard venting option; with this, the boiler
can be sited up to 120 equivalent feet from
the vent termination (for the VFC 45-225
with nat.gas only,
up to 240’ equivalent). The
actual vent travel allowance is reduced for
fittings in accordance with
Table 3
. – e.g.
for a VFC 15-150 using 6 x 90º PVC elbows,
the maximum lineal measure is 90 feet
(120’–(6 x 8’= 48) = 72’). For the 15-150
model, vent installations requiring only short
travel can be satisfied using 2’ or 2½” pipe.
Table 3 - Max. Venting Length (each side)
Pipe Size
Max. Equiv.Length
2” (15-150 only)
50 feet (each side)
2½” (15-150 only)
70 feet
3" (15-150)
120 feet
3" (45-225 propane)
120 feet
3" (45-225 nat. gas)
240 feet
90° long elbow
allow 5’ equiv.
90° vent elbow
allow 8’ equiv.
45° elbow
allow 3’ equiv.
Note such measures pertain separately to
each the exhaust and intake, but unused
intake travel cannot be added to the exhaust.
For 3" piping, a 3"x 2” bushing is to be
used in the inlet piping within 3 feet of
