Bryant 355BAV Installation, Start-Up, And Operating Instructions Manual page 25

Vent Pipe
General
Furnace vent connection must be attached as shown in Fig. 25.
WARNING
!
CARBON MONOXIDE POISONING AND
PROPERTY DAMAGE HAZARD
Failure to follow this warning could result in property
damage, personal injury, or death.
Vent pipes must be airtight.
NOTE: A 2- -in. (51 mm) diameter pipe must be used within the
furnace casing. Make all pipe diameter transitions outside furnace
casing per Fig. 24.
The minimum vent pipe length for these furnaces is 5 ft. (1.5 M).
Short pipe lengths (5- -8 ft. (1.5- -2.4 M)) may discharge condensate
droplets. These condensate droplets may be undesirable. A 12- -in.
(305 mm). minimum offset pipe section is recommended to reduce
excessive condensate droplets from exiting vent pipe outlet. (See
Fig. 30.)
Attachment of Vent Pipe
NOTE: Vent pipe system has the same diameter and same length
as combustion air pipe as mentioned in section "Combustion Air
Pipe and Vent Pipe Diameter."
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit component
damage.
Vent pipe must be installed and fully seated against inducer
housing. Clamp must be tightened to prevent any
condensate leakage.
1. Determine location of vent pipe connection to inducer hous-
ing as shown in Fig. 25 for application.
2. Verify synthetic rubber inducer housing outlet cap and
clamp are installed on appropriate unused inducer housing
connection and that clamp is tight.
3. Install combustion- -air pipe grommet (factory- -supplied in
loose parts bag) into selected furnace casing vent pipe hole.
(See Fig. 18.)
4. Be certain that mating surfaces of inducer housing connec-
tion synthetic rubber coupling, and 2- -in. (51 mm) diameter
vent pipe are clean and dry. Assemble the synthetic rubber
vent coupling (with 2 loose clamps) onto inducer housing
connection. Insert the 2- -in. (51 mm) diameter vent pipe
through the synthetic rubber coupling and fully into inducer
housing connection until it touches a stop inside the inducer
housing outlet. Tighten the screws on both clamps to
15- -in- -lb. of torque.
NOTE: Starting at furnace, slope vent pipe a minimum of 1/4- -in.
(6 mm). per linear ft back toward furnace with no sags between
hangers.
5. Install casing hole filler cap (factory- -supplied in loose parts
bag) in unused vent pipe casing hole.
Vent Termination
General
Combustion- -air (direct vent/2- -pipe system only) and vent pipe
must terminate outside structure, either through sidewall or roof.
For vent termination clearance, refer to Fig. 34 for Direct
Vent/2- -Pipe system and Fig. 35 for Ventilated Combustion Air
option.
Roof termination is preferred since it is less susceptible to damage
or contamination, and it has less visible vent vapors. Sidewall
termination require sealing or shielding of building surfaces with a
corrosive resistance material due to corrosive combustion products
of vent system.
NOTE: (Direct Vent/2- -Pipe system ONLY) A factory accessory
termination kit MUST be used. See section "Vent Termination Kit
(Direct Vent/2- -Pipe System Only)" in this instruction.
When determining appropriate location for termination, consider
the following guidelines:
1. Comply with all clearance requirements stated in Fig. 34 or
Fig. 35 per application.
2. Termination or termination kit should be positioned where
vent vapors will not damage plants/shrubs or air condition-
ing equipment.
3. Termination or termination kit should be positioned so that
it will not be affected by wind eddy, such as inside building
corners, nor by recirculation of flue gases, airborne leaves,
or light snow.
4. Termination or termination kit should be positioned where it
will not be damaged by or subjected to foreign objects such
as stones, balls, etc.
5. Termination or termination kit should be positioned where
vent vapors are not objectionable.
Extended Exposed Sidewall Pipes
Sidewall combustion air pipe termination (direct vent/2- -pipe
system only) and vent pipe termination may be extended beyond
area shown in Fig. 31 or in Fig. 32 per application in outside
ambient by insulating pipe as indicated in Table 7.
1. Determine combustion air pipe diameter (direct vent/2- -pipe
system only) and vent pipe diameter, as stated above, using
total pipe length and number of elbows.
2. Using winter design temperature (used in load calculations),
find appropriate temperature for your application and fur-
nace model.
3. Determine required insulation thickness for exposed pipe
length(s).
NOTE: Pipe length (ft/M) specified for maximum pipe lengths
located in unconditioned spaces cannot exceed total allowable pipe
length as specified in Table 8.
Vent Termination Kit (Direct Vent / 2- -Pipe System Only)
NOTE: Always refer to the instructions in termination kit for the
latest version.
Combustion air and vent pipes MUST terminate outside structure.
A factory accessory termination kit must be installed as shown in
Table 6. There are four options of vent/combustion air termination
kits available as shown in Table 6.
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