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·
Both the exhaust vent and air intake run the length of the
chimney.
·
No other gas fired appliance or fireplace (solid fuel) is
vented into the chimney.
·
The top of the chimney MUST be sealed flush or crowned
up to seal against rain or melting snow so ONLY the piping
protrudes.
·
The termination clearances shown in Figure 7 are main-
tained.
15. Furnace applications with vertical vents requiring vent diam-
eter increaser fittings must have increaser fittings installed
in vertical portion of the vent. Condensate will be trapped in
the vent if the vent diameter is increased prior to having an
elbow turned upward. This could cause nuisance tripping of
the pressure switch.
Piping Insulation Guidelines
NOTE: Use closed cell, neoprene insulation or equivalent. If Fiber-
glass or equivalent insulation is used it must have a vapor barrier.
Use R values of 7 up to 10¢, R--11 if exposure exceeds 10¢. If Fiber-
glass insulation is used, exterior to the structure, the pipe MUST be
boxed in and sealed against moisture.
1.
When the vent or combustion air pipe height above the roof
exceeds 30², or if an exterior vertical riser is used on a hori-
zontal vent to get above snow levels, the exterior portion
MUST be insulated.
2.
When combustion air inlet piping is installed above a sus-
pended ceiling, the pipe MUST be insulated with moisture
resistant insulation such as Armaflex or other equivalent
type of insulation.
3.
Insulate combustion air inlet piping when run in warm, humid
spaces such as basements.
Sizing Combustion Air and Vent Pipe
Consult Table 3 or Table 4 to select the proper diameter exhaust
and combustion air piping. Exhaust and combustion air piping is
sized for each furnace Btuh size based on total lineal vent length
(on inlet or outlet side), and number of 90° elbows required. Two
45° elbows can be substituted for one 90° elbow. The elbow or el-
bows used for vent termination outside the structure ARE counted,
including elbows needed to bring termination above expected
snow levels. The elbow inside the furnace on the *9MPD IS NOT
included in the count.
Pipe Diameter Table
Table 3
N9MP1 & *9MPD Models
50,000, 75,000 & 80,000 Btuh Furnaces
40¢ & (5) 90° elbows with 2² PVC pipe or
70¢ & (5) 90° elbows with 3² PVC pipe
100,000 Btuh Furnace
40¢ & (5) 90° elbows with 3² PVC pipe or
70¢ & (5) 90° elbows with 3² PVC pipe &
Long Vent Kit (See Tech. Manual)
125,000 Btuh Furnace
40¢ & (5) 90° elbows with 3² PVC pipe
Elbows are DWV Long Radius Type for 2
If more than five elbows are required, reduce the length of
both the inlet and exhaust pipes 5¢ for each additional elbow
used.
440 01 1020 02
NOTE: It is allowable to use larger diameter pipe and fitting than
shown in the tables but not smaller diameters than shown.
Table 4
If more than five elbows are required, reduce the length of
both the inlet and exhaust pipes 5¢ for each additional elbow
used.
For "Concentric Termination Kit" Venting table, see
"Section 11" in this manual.
Vent Termination Clearances
CARBON MONOXIDE POISONING, FIRE AND EXPLOSION
HAZARD
Failure to properly vent this furnace can result in death,
personal injury and/or property damage.
Inlet and outlet pipes may NOT be vented directly above
each other.
1.
For "Concentric Termination Kit" clearances, see Figure 45,
Figure 46, Figure 47, Figure 48 and Figure 49 in "Section 10"
in this manual.
2.
3.
4.
5.
and 3
vents.
²
²
6.
Pipe Diameter Table
N9MP2 Models
50,000 & 80,000 Btuh Furnaces
40¢ & (5) 90° elbows with 2² PVC pipe or
70¢ & (5) 90° elbows with 3² PVC pipe
75,000 Btuh Furnaces
25¢ & (3) 90° elbows with 2² PVC pipe or
40¢ & (5) 90° elbows with 2² PVC pipe &
Long Vent Kit (See Tech. Manual) or
70¢ & (5) 90° elbows with 3² PVC pipe
100,000 Btuh Furnace
40¢ & (5) 90° elbows with 3² PVC pipe or
70¢ & (5) 90° elbows with 3² PVC pipe &
Long Vent Kit (See Tech. Manual)
125,000 Btuh Furnace
40¢ & (5) 90° elbows with 3² PVC pipe
Elbows are DWV Long Radius Type for 2
!
Determine termination locations based on clearances spe-
cified in following steps and as shown in Figure 7,
Figure 19, through Figure 27.
The vent termination must be located at least 12² above
ground or normally expected snow accumulation levels.
Do NOT terminate over public walkways. Avoid areas where
condensate may cause problems such as above planters,
patios, or adjacent to windows where steam may cause fog-
ging.
The vent termination shall be located at least 4¢ horizontally
from any electric meter, gas meter, regulator, and any relief
equipment. These distances apply ONLY to U.S. installa-
tions.
The vent termination is to be located at least 3¢ above any
forced air inlet located within 10¢ ; and at least 10¢ from a
combustion air intake of another appliance, except another
direct vent furnace intake.
In Canada, the Canadian Fuel Gas Code takes precedence
over the preceding termination instructions.
and 3
vents.
²
²
11
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