International comfort products N9MP1 Installation Instructions Manual page 12

9. Use DWV type long radius elbows whenever possible, as
they provide for the minimum slope on horizontal runs and
they provide less resistance in the vent system. If DWV el-
bows cannot be used, use two, 45° elbows when possible.
On horizontal runs the elbows can be slightly misaligned to
provide the correct slope.
10. All horizontal pipe runs MUST be supported at least every
five feet with galvanized strap or other rust resistant materi-
al. NO sags or dips are permitted.
11. All vertical pipe runs MUST be supported every six feet
where accessible.
12. The minimum pipe run length is 2¢.
13. The piping can be run in the same chase or adjacent to sup-
ply or vent pipe for water supply or waste plumbing. It can
also be run in the same chase with a vent from another 90+
furnace.
NOTE: In NO case can the piping be run in a chase where
temperatures can exceed 140° F. or where radiated heat
from adjacent surfaces would exceed 140° F.
14. The vent outlet MUST be installed to terminate in the same
atmospheric pressure zone as the combustion air inlet.
15. The vent system can be installed in an existing unused
chimney provided that:
·
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 & Figure 8
are maintained.
16. Furnace applications with vertical vents requiring vent di-
ameter 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.
Combustion Air and Vent 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, hu-
mid spaces.
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
12
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.
NOTE: It is allowable to use larger diameter pipe and fitting than
shown in the tables but not smaller diameters than shown.
Pipe Diameter Table
Table 4
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
If more than five elbows are required, reduce the length of
both the inlet and exhaust pipes 5¢ for each additional elbow
used.
NOTE: It is allowable to use larger diameter pipe and fitting than
shown in the tables but not smaller diameters than shown.
For "Concentric Termination Kit" Venting table, see
"Section 11" in this manual.
Vent Termination Clearances
WARNING
!
CARBON MONOXIDE POISONING.
Failure to properly vent this furnace could result in
death or personal injury.
Inlet and outlet pipes may NOT be vented directly
above each other.
1. Determine termination locations based on clearances spe-
cified in following steps and as shown in Figure 7, Figure 8,
Figure 20, through Figure 28.
For "Concentric Termination Kit" clearances, see Figure 29,
thru Figure 33 in "Section 5" in this manual.
2. For Single Pipe Installation, models N9MP1 or *9MPD, refer
to Figure 8 for vent termination clearances.
3. For Direct Vent Installation, models N9MP2 or *9MPD, refer
to Figure 7 for vent termination clearances.
and 3 vents.
² ²
N9MP2 Models
and 3 vents.
² ²
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