PG92MSA: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
46
Two-Pipe and Single-Pipe Terminations
Single  and  two  pipe  vent  must  be  installed  as  shown  in  Fig. 40  and
Fig. 41. Maintain the required separation distance between vents or pairs
of  vents  as  shown  in  Fig. 40  and  Fig. 41  and  all  clearance  shown  in
Fig. 43 and Fig. 44.
Cut  the  required  number of holes  in  the  roof  or  sidewall  for  vent  and
(when  used)  combustion  air  pipes.  Sidewall  holes  for  two-pipe  vent
terminations should be side-by-side, allowing  space between  the pipes
for the elbows to fit on the pipes.
Holes in the roof for direct-vent two-pipe terminations should be spaced
no more than 18 in. (457 mm) apart to help avoid vent gas recirculation
into combustion air intake.
Termination  elbows  will  be  installed  after  the  vent  and  (if  used)
combustion air pipe is installed.
Sidewall Terminations
Concentric Vent
NOTE: Follow the instructions of the vent terminal manufacturer. These
instructions are provided as a reference only.
Determine an appropriate location for termination kit using the
guidelines provided in section “Locating The Vent Termination” in
this instruction.
1. Cut one 4-in. diameter hole for 2-in. kit, or one 5-in. diameter hole
for 3-in. kit.
2. Loosely  assemble  concentric  vent/combustion  air  termination
components together using instructions in kit.
3. Slide assembled kit with rain shield REMOVED through hole.
NOTE: Do not allow insulation or other materials to accumulate inside
of pipe assembly when installing it through hole.
4. Locate  assembly  through  sidewall  with  rain  shield  positioned  no
more than 1-in. (25 mm) from wall as shown in Fig. 40.
5. Disassemble  loose  pipe  fittings.  Clean  and  cement  using  same
procedures  as  used  for  system  piping.  DO  NOT  CEMENT
POLYPROPYLENE FITTINGS.
2-Pipe and 1-Pipe Vent Termination
NOTE: Follow the instructions of the vent terminal manufacturer. These
instructions are provided as a reference, only.
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 Fig. 40 and Fig. 48.
NOTE:  For  applications  using  vent  pipe  option  indicated  by  dashed
lines in Fig. 40 and Fig. 41, rotate vent elbow 90_ from position.
4. Disassemble  loose  pipe  fittings.  Clean  and  cement  using  same
procedures  as  used  for  system  piping.  DO  NOT  CEMENT
POLYPROPYLENE FITTINGS.
(Direct Vent / 2-Pipe System ONLY)
When  two  or  more  furnaces  are  vented  near  each  other,  two  vent
terminations  may  be  installed  as  shown  in  Fig. 40,  but  next  vent
termination,  or  pair  of  vent  terminations,  must  be at  least  36  in.  (914
mm)  away  from  the  first  two  terminations.  It  is  important  that  vent
terminations be made as shown in Fig. 40 to avoid recirculation of vent
gases.
Inducer Outlet Restrictor
To improve efficiency and operation of 40K, 60K, 100K or 120K 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  shown  in  the  footnote  of  Table 14  -Maximum  Equivalent
Vent Length. The outlet restrictor for 40K models is shipped in the loose
parts  bag.  See  Table 14  for  usage,  part  numbers  and  sourcing  of  60K,
100K, and 120K inducer outlet restrictors.
To determine if the outlet restrictor is required, see Table 14. Failure to
use an outlet restrictor on the 40K input model when required may
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 on inside
outlet of the inducer assembly.
3. Snap the outlet restrictor in place.
4. Re-install the vent elbow.
5. Torque vent elbow clamp 15-lb-in.
NOTICE
!
RECOMMENDED SUPPORT FOR VENT TERMINATIONS
It is recommended that rooftop vent terminations in excess of 36 inches
(1  M)  in  vertical  length  be  supported  by  EITHER  the  Direct  Vent
Termination  Kit  shown  in  Table 12  or  by  field-supplied  brackets  or
supports fastened to the structure.
NOTICE
!
RECOMMENDED SUPPORT FOR VENT 
TERMINATIONS
It  is  recommended  that  sidewall  vent  terminations  in  excess  of  24
inches (0.6 M) in vertical length be supported by EITHER the Direct
Vent Termination Kit  shown in  Table 12 or by field-supplied brackets
or supports fastened to the structure.