ICP *9MPT050F12 Installation Instruction page 12

5. Use of vertical piping is preferred because there will be
some moisture in the flue gases that may condense as it
leaves the vent pipe.
6. The vertical vent pipe MUST be supported so that no weight
is allowed to rest on the combustion blower.
7. Exhaust vent piping or air inlet piping diameter MUST NOT
be reduced.
8. All exhaust vent piping from the furnace to termination
MUST slope upwards. A minimum of
required to properly return condensate to the furnace drain
system.
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 maximum pipe length is 40¢ total in the inlet or outlet
side of the system. Up to five, 90° elbows can be used on the
inlet or the outlet. With the Concentric Vent Termination Kits
(NAHA001CV or NAHA002CV), the maximum pipe length
is 35¢ with 4 90° elbows. If more elbows are required, reduce
the length of both the inlet and exhaust pipes 5¢ for each
additional elbow used. (See Table 3 or Table 4).
13. The minimum pipe run length is 2¢.
14. 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.
15. The vent outlet MUST be installed to terminate in the same
atmospheric pressure zone as the combustion air inlet.
16. 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 are main-
tained.
17. 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-
12
glass insulation is used, exterior to the structure, the pipe MUST
be boxed in and sealed against moisture.
1.
2.
1
/ ² per foot of run is
4
3.
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.
1.
2.
3.
Table 3
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.
Table 4
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.
* Feet of pipe is whichever pipe run is the longest, either inlet
or outlet side.
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.
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.
Insulate combustion air inlet piping when run in warm, hu-
mid spaces.
Double Pipe Installation- -If installing as a direct--vent ap-
pliance, consult Table 4 to select the proper diameter ex-
haust 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.
Single Pipe Installation- -If installing as a non--direct vent
appliance, (single outlet pipe and no inlet pipe) refer to
Table 3. The table shows the maximum number of elbows
allowed with any given pipe diameter and length of run.
Use of Elbows- -Two 45° elbows can be substituted for one
90° elbow. The elbow or elbows used for vent termination
outside the structure ARE counted, including elbows need-
ed to bring termination above expected snow levels.
Pipe Diameter Table
Single Piping ONLY
50,000 & 75,000 Btuh Furnaces
40¢ ¢ ¢ ¢ & (5) 90° elbows with 2² PVC pipe
100,000 Btuh Furnace
40¢ ¢ ¢ ¢ & (5) 90° elbows with 3² PVC pipe
125,000 Btuh Furnace
40¢ ¢ ¢ ¢ & (5) 90° elbows with 3² PVC pipe
Pipe Diameter Table
Dual Piping ONLY
75,000 Btuh Furnaces
50,000 & 75,000 Btuh Furnaces
40¢ ¢ ¢ ¢ & (5) 90° elbows with 2² PVC pipe
100,000 Btuh Furnace
40¢ & (5) 90° elbows with 3² PVC pipe
125,000 Btuh Furnace
40¢ & (5) 90° elbows with 3² PVC pipe
and 3 vents.
² ²
and 3 vents.
² ²
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