11
V
ENT
/F
LUE
P
IPE
& C
OMBUSTION
A
IR
P
IPE
This manual will refer to the pipe that discharges products of
combustion to the outdoors as the "vent" pipe or "flue" pipe.
The pipe that supplies air for combustion to the furnace will
be referred to as the "intake" pipe or "combustion air" pipe.
A condensing gas furnace achieves its high level of efficiency
by extracting almost all of the heat from the products of
combustion and cooling them to the point where condensation
takes place. Because of the relatively low flue gas temperature
and water condensation requirements, PVC or ABS are typically
used venting and intake pipe materials. In Canada ABS is
not an approved vent pipe material, but it is permissible to
use as combustion air pipe material.
In addition to PVC and ABS pipe and fittings, Innoflue
®
by
Centrotherm Eco Systems and PolyPro
®
by M&G Duravent are
also approved vent and combustion air materials for
installations in the U.S.A. and Canada. Manufacturers
Installation instructions for these products must be followed.
These products have specific instructions for installing,
joining and terminating. Do not mix materials or components
of one manufacturer with materials or components of another
manufacturer.
All furnaces are manufactured with 2" vent / intake pipe and
connectors. For furnaces requiring installation of 3" pipe,
the transition from 2" to 3" should be done as close to the
furnace as practically possible.
This furnace must not be connected to Type B, BW, or L vent
or vent connector, and must not be vented into any portion
of a factory built or masonry chimney except when used as a
pathway for PVC as described later in this section. Never
common vent this appliance with another appliance or use a
vent which is used by a solid fuel appliance. Do not use
commercially available “no hub connectors” other than those
shipped with this product.
It is the responsibility of the installer to follow the
manufacturers’ recommendations and to verify that all vent/
flue piping and connectors are compatible with furnace flue
products. Additionally, it is the responsibility of the installer
to ensure that all piping and connections possess adequate
structural integrity and support to prevent flue pipe
separation, shifting, or sagging during furnace operation.
D
UAL
C
ERTIFICATION
: N
ON
-D
IRECT
/D
IRECT
V
ENT
This furnace is dual certified and may be installed as a non-
direct vent (single pipe) or direct vent (dual pipe) appliance.
A
non-direct vent
installation requires only a vent/flue pipe,
while a
direct vent
installation requires both a vent/flue pipe
and a combustion air intake pipe. Refer to the appropriate
section for details concerning piping size, length, number of
elbows, furnace connections, and terminations.
T
O
AVOID
BODILY
INJURY
,
FIRE
OR
EXPLOSION
,
SOLVENT
CEMENTS
MUST
BE
KEPT
AWAY
FROM
ALL
IGNITION
SOURCES
(
I
.
E
.,
SPARKS
,
OPEN
FLAMES
,
AND
EXCESSIVE
HEAT
)
AS
THEY
ARE
COMBUSTIBLE
LIQUIDS
.
A
VOID
BREATHING
CEMENT
VAPORS
OR
CONTACT
WITH
SKIN
AND
/
OR
EYES
.
WARNING
M
ATERIALS
AND
J
OINING
M
ETHODS
Two-three-inch nominal diameter PVC Schedule 40 pipe
meeting ASTM D1785, PVC primer meeting ASTM F656, and
PVC solvent cement meeting ASTM D2564 specifications must
be used. Fittings must be DWV type fittings meeting ASTM
D2665 and ASTM D3311. Carefully follow the manufacturer’s
instructions for cutting, cleaning, and solvent cementing of
PVC.
The use of Schedule 40 PVC cellular core DWV meeting ASTM
F891-1 or ABS cellular core (Foam Core) plastic pipe is also
acceptable as a flue/vent and intake pipe material. PVC
primer meeting ASTM F656 and PVC solvent cement meeting
ASTM D2564 specifications must be used. Fittings must be
DWV type fittings meeting ASTM D2665 and ASTM D3311.
Carefully follow the manufactures instructions for cutting,
cleaning and solvent cementing of PVC.
For Canadian installations; field supplied PVC venting
materials must be UL S636 listed. NOTE: Requirement does
not apply to the combustion air pipe.
As an alternative to PVC pipe, primer, solvent cement, and
fittings, ABS materials which are in compliance with the
following specifications may be used. Two-or-three-inch ABS
Schedule 40 pipe must meet ASTM D1527 and, if used in
Canada, must be CSA listed. Solvent cement for ABS to ABS
joints must meet ASTM D2235 and, if used in Canada, must
be CSA listed. The solvent cement for the PVC to ABS
transition joint must meet ASTM D3138. Fittings must be
DWV type fittings meeting ASTM D2661 and ASTM D3311
and, if used in Canada, must be CSA listed. Carefully follow
the manufacturers’ instructions for cutting, cleaning, and
solvent cementing PVC and/or ABS.
All 90° elbows must be medium radius (1/4 bend DWV) or
long radius (Long sweep 1/4 bend DWV) types conforming
to ASTM D3311. A medium radius (1/4 bend DWV) elbow
measures 3 1/16” minimum from the plane of one opening
to the center line of the other opening for 2” diameter pipe,
and 4 9/16” minimum for 3” pipe.
