Manual

8 - COMBUSTION AIR AND VENT PIPE
8.1 Connections And Termination
Boilers for connection to gas vents or chimneys, vent
installations shall be in accordance with “Venting of
Equipment” of the National Fuel Gas Code, ANSI Z223.1/
NFPA 54, or “Venting Systems and Air Supply for
Appliances”, of the Natural Gas and Propane Installation
Code, CAN/CSA B149.1, or applicable provisions of local
building codes.
Provisions for combustion and ventilation air must be
in accordance with section, Air For Combustion and
Ventilation, of the National Fuel Gas Code, ANSI 2223.1/
NFPA54, National Gas and Propane Installation Code, CAN/
CGA-B 149.1, in absence of such requirements to the
Authority having jurisdiction.
Boilers require dedicated direct vent system. All air for
combustion is taken directly from outdoors through
combustion air intake pipe. All ue products are discharged
to outdoors through vent pipe.
1. See Figures 5 and 6 for two pipe combustion air
and vent pipe roof and sidewall termination. Roof
termination is preferred. Combustion air and vent pipes
must terminate together in same atmospheric pressure
zone as shown.
2. Use of concentric vent termination see Figures 7-9for
proper setup.
3. For Canadian installations all plastic venting material
must be listed to ULC S636.
4. Construction through which vent and air intake pipes
may be installed is maximum 24 inches, minimum ¼”
thickness.
5. See Table 5 for combustion air and vent pipe ttings
approved material and standards.
6. Canada construct all combustion air and vent pipes
for this unit of ULC S636 listed schedule-40 CPVC,
schedule-40 PVC, PVC-DWV or ABS-DWV pipe and pipe
cement. SDR pipe is not approved in Canada.
• First 3 feet (900mm) of venting must be readily
available for visual inspection.
• Specied primers and glues of certied vent
system must be from single manufacturer, and not
intermixed with other manufacturer’s vent system
parts.
• Components of the certied system must not be
interchanged with other vent systems, or unlisted pipe
and/or ttings.
NOTICE
Transition from 2” pipe to 3” pipe must be made in
vertical run.
7. Boiler combustion air and vent pipe connections are 2”
but must increase to 3”. Due to potential for ue gas
temperatures above 155°F, rst 30” of supplied vent
pipe is CPVC while remaining vent pipe can be PVC. Any
replacement of rst 30” of vent pipe must be made with
CPVC.
8. Covering non-metallic vent pipe and ttings with thermal
insulation shall be prohibited.
TABLE 4
Maximum Allowable Temperatures
Of Typical Non-Metallic Vent Material
Material
HDT
RTI
Standard
°F °C °F °C
PVC 158 70 – –
ASTM F 891 *
ASTM D2665 **
ASTM D1785 **
ASTM D2241 **
CPVC 210 100 – –
ASTM D2846 **
ASTM F441 **
ASTM F442 **
ABS 180 82 – –
ASTM D2661 ***
ASTM F628 ***
* Allowable temperatures based on Classications covered in ASTM
D4396 [Deection Temperatures under Load (264psi) (1819 KPa)].
** Allowable temperatures based on Classications covered in ASTM
D1784 [Deection Temperatures under Load (264psi) (1819 KPa)].
*** Allowable temperatures based on Classications covered in ASTM
D3965 [Deection Temperatures under Load (264psi) (1819 KPa)].
Length of pipe is counted from end of supplied 2” CPVC
pipe exiting boiler. Termination is not counted in “Total
Equipment Length.”
Table 5 - Combustion air and vent pipe ttings
must conform with the following:
Item Material Standards
Vent Pipe
and Fittings
PVC schedule 40 ANSI/ASTM D1785
PVC - DWV ANSI/ASTM D2665
CPVC schedule 40
ANSI/ASTM D1784/
F441
SDR-21 & SDR-26 PVC ANSI/ASTM D2241
ABS-DWV ANSI/ASTM D2661
Schedule 40ABS ANSI/ASTM F628
PP (Polypropylene)
Pipe and Components
UL 1738
ULC S636-08
Pipe
Cement/
Primer
PVC ANSI/ASTM D2564
CPVC ANSI/ASTM F493
Schedule 40 ABS ANSI/ASTM D2235
• IPEX is approved vent manufacturer in Canada listed
to ULC-S636.
• IPEX System 636 Cements and Primers are approved
in Canada listed to ULC-S636.
Use of cellular core PVC (ASTM F891), cellular core CPVC, or Radel
®
,
(Polyphenolsulfone) in venting systems shall be prohibited.
WARNING
Use of cellular core PVC for venting ue gas could
result in death, or serious injury.
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