International comfort products N9MSB Installation Instructions Manual page 49

INSTALLATION INSTRUCTIONS
5. Disassemble loose pipe fittings. Clean and cement using
same procedures as used for system piping. DO NOT
CEMENT POLYPROPYLENE FITTINGS.
Two-Pipe and Single-Pipe Vent Termination
NOTE: Follow the instructions of the vent terminal
manufacturer. These instructions are provided as a reference,
only.
NOTICE
RECOMMENDED SUPPORT
TERMINATIONS
It is recommended that side−wall vent terminations in
excess of 24 inches (0.6 M) in vertical length be sup-
ported by EITHER the Direct Vent Termination Kit in
Table 12 or by field-supplied brackets or supports
fastened to the structure.
Determine an appropriate location for termination kit using the
guidelines provided in section "Locating The Vent Termination"
in this instruction.
1. Cut two holes, one for each pipe, of appropriate size for
pipe size being used.
2. Loosely install elbow in bracket (if used) and place
assembly on combustion−air pipe.
3. Install bracket as shown in Figure 44 and Figure 46.
NOTE: For applications using vent pipe option indicated by
dashed lines in Figure 47 and Figure 48, rotate vent elbow 90_
from position.
440 01 4101 03
4. Disassemble loose pipe fittings. Clean and cement using
(Direct Vent / Two-Pipe System ONLY)
When two or more furnaces are vented near each other, two
vent terminations may be installed as shown in Figure 47, but
next vent termination, or pair of vent terminations, must be at
least 36−in. (914 mm) away from first two terminations. It is
important that vent terminations be made as shown in
Figure 47 to avoid recirculation of gases.
Inducer Outlet Restrictor
FOR VENT
(PSC models only)
To improve efficiency and operation of 40,000 BTUH input
models on very short vent systems, an inducer outlet restrictor
is required to be installed on the outlet of the inducer assembly.
The outlet restrictor is shipped in the loose parts bag.
To determine if the outlet restrictor is required, see Table 14
NOTE:
result in flame disturbance or flame sense lockout.
To install the outlet restrictor:
1. Remove the vent elbow from the inducer outlet
2. Align the lock tabs on the outlet restrictor with the slots
3. Snap the outlet restrictor in place.
4. Re-install the vent elbow
5. Torque vent elbow clamp 15 lb−in.
Specifications subject to change without notice.
Gas Furnace: N9MSB, N9MSE
same procedures as used for system piping. DO NOT
CEMENT POLYPROPYLENE FITTINGS.
Failure to use an outlet choke when required may
on inside outlet of the inducer assembly.
49