13
located in this section for specific details on termination construc-
tion.
• All terminations (flue and/or intake) must be located at
least 12 inches above ground level or the anticipated
snow level.
• Vent terminations (non-direct and direct vent) must
terminate at least 3 feet above any forced air inlet located
within 10 feet.
NOTE: This provision does not apply to the combustion
air intake termination of a direct vent application.
• The vent termination of a non-direct vent application must
terminate at least 4 feet below, 4 feet horizontally from, or
1 foot above any door, window, or gravity air inlet into any
building.
• The vent termination of a direct vent application must
terminate at least 12 inches from any opening through
which flue gases may enter a building (door, window, or
gravity air inlet).
• The vent termination of vent pipe run vertically through a
roof must terminate at least 12 inches above the roof line
(or the anticipated snow level) and be at least 12 inches
from any vertical wall (including any anticipated snow
build up).
• A vent termination shall not terminate over public walkways
or over an area where condensate or vapor could create
a nuisance or hazard or could be detrimental to the
operation of regulators, relief valves, or other equipment.
• The combustion air intake termination of a direct vent
application should not terminate in an area which is
frequently dusty or dirty.
12"
Non-Direct Vent
Vent/Flue Termination
No Terminations
Above Walkway
12"
min.
4'
min.
Non-Direct Vent
Vent/Flue Termination
Direct Vent
Vent/Flue Termination
<10'
Forced Air
Inlet
Non-Direct Vent
&
Direct Vent
Vent/Flue Terminations
Grade or Highest
Anticipated
Snow Level
3' min.
12" min.
4' min.
12" min.
Vent Termination Clearances
NOTE: In Canada, the Canadian Fuel Gas Code takes precedence
over the preceding termination restrictions.
CANADIAN VENTING R EQUIREMENTS
In Canada, venting must conform to the requirements of the cur-
rent CAN/CSA-B149 Installation Code. Use only CSA listed two or
three inch diameter PVC or ABS pipe, solvent cement, and fittings
throughout. Carefully follow the manufacturers’ instructions for
cutting, cleaning, and solvent cementing PVC and/or ABS.
The vent can be run through an existing unused chimney provided
the space between the vent pipe and the chimney is insulated and
closed with a weather-tight, corrosion-resistant flashing.
MATERIALS AND JOINING METHODS
WARNING
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.
Two- or three-inch nominal diameter PVC Schedule 40 pipe meet-
ing ASTM D1785, PVC primer meeting ASTM F656, and PVC sol-
vent 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.
As an alternative to PVC pipe, primer, solvent cement, and fittings,
ABS materials which are in compliance with the following specifi-
cations 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 centerline of the
other opening for 2” diameter pipe, and 4 9/16” minimum for 3”
pipe.
PROPER VENT/FLUE AND C OMBUSTION AIR PIPING PRACTICES
Adhere to these instructions to ensure safe and proper furnace
performance. The length, diameter, and number of elbows 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 sag-
ging, joint separation, and/or detachment from the furnace. Hori-
zontal runs of vent/flue piping must be supported every three feet
and must maintain a 1/4 inch per foot downward slope, back to-
wards the furnace, to properly return condensate to the furnace’s
drain system. Allowances should be made for minor expansion
and contraction due to temperature variations. For this reason,
particular care must be taken to secure piping when a long run is
followed by a short offset of less than 40 inches.
Precautions should be taken to prevent condensate from freezing
inside the vent/flue pipe and/or at the vent/flue pipe termination. All
vent/flue piping exposed to freezing temperatures below 35°F for
extended periods of time must be insulated with 1/2” thick closed
cell foam. Also all vent/flue piping exposed outdoors in excess of
the terminations shown in this manual (or in unheated areas)
must be insulated with 1/2” thick closed cell foam. Inspect piping
for leaks prior to installing insulation.
TERMINATION L OCATIONS
NOTES: Refer to Section IV, Location Requirements and
Considerations for combustion air contaminant restrictions.
The following bullets and diagram describe the restrictions con-
cerning the appropriate location of vent/flue pipe and combustion
air intake pipe (when applicable) terminations. Refer to Non-Di-
rect Vent (Single Pipe) Piping and Direct Vent (Dual Pipe) Piping