16
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- or 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 pipe
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 fol-
low the manufactures instructions for cutting, cleaning and
solvent cementing of PVC.
For Canadian installations; all PVC pipe, fittings and join-
ing materials must be UL S636 listed.
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 solid wall ABS Schedule 40 pipe must meet ASTM
D1527 and, if used in Canada, must be CSA listed or, two-
or-three-inch cellular core ABS Schedule 40 pipe must meet
ASTM F628 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 manu-
facturers’ 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 centerline of
the other opening for 2” diameter pipe, and 4 9/16” minimum
for 3” pipe.
The use of two short radius 45 degree elbows is permit-
ted to provide clearance to refrigerant piping above the
furnace.
P
ROPER
V
ENT
/F
LUE
AND
C
OMBUSTION
A
IR
P
IPING
P
RACTICES
Adhere to these instructions to ensure safe and proper fur-
nace performance. The length, diameter, and number of el-
bows of the vent/flue pipe and combustion air pipe (when
applicable) affects the performance of the furnace and must
be carefully sized. All piping must be installed in accordance
with local codes and these instructions.
Piping must be adequately secured and supported to prohibit
sagging, joint separation, and/or detachment from the fur-
nace. Horizontal runs of vent/flue and combustion air pip-
ing must be properly supported. PVC pipe supports must be
no more than 5' apart. For ABS pipe, supports must be no
more than 3' apart. Horizontal pipe runs must maintain a
1/4 inch per foot downward slope, back towards the furnace,
to properly return condensate to the furnace’s drain system.
PREFERRED
Figure 6
TRANSITION NO LESS
THAN 45 DEGREES TO
HORIZONTAL PLANE TO
AVOID CREATING A WATER
TRAP IN VENT PIPING.
ACCEPTABLE
Figure 7
