Bryant 340AAV Installation, Start-Up, And Operating Instructions Manual page 43

FURNACE
NOT IN
HORIZONTAL
SECTION
Fig. 39 - - Combustion- -Air and Vent Pipe Diameter
Transition Location and Elbow Configuration
Attachment of Combustion Air Intake Housing
Plug Fitting
The combustion-air intake plug fitting must be installed in unused
combustion air intake housing. This fitting must be attached by
using RTV sealant, or by drilling a 1/8-in. (3 mm) hole in fitting,
using hole in intake housing as a guide. Install a field-supplied
No. 6 or No. 8 sheet metal screw.
NOTE: DO NOT OVERTIGHTEN SCREW. Breakage of intake
housing or fitting may cause air leakage to occur.
A plugged drain connection has been provided on this fitting for
use when moisture is found in combustion air intake pipe and
combustion box. If use of this drain connection is desired, drill
out fitting's tap plug with 3/16-in. (5 mm)drill and connect a
field-supplied 3/8-in. (10 mm) tube. This tube should be routed to
open condensate drain for furnace and A/C (If used), and should
be trapped, as shown in Fig. 40.
NOTE:
(Direct Vent/2-Pipe System ONLY) Moisture in
combustion air intake may be a result of improper termination.
Ensure combustion air pipe termination is similar to those as
shown in Fig. 42 so that it will not be susceptible to area where
light snow or other sources of moisture could be pulled in.
VENT PIPE
General
Furnace vent connection must be attached as shown in Fig. 35.
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. 39.
The minimum vent pipe length for these furnaces is 5 ft. Short
pipe lengths (5 - - 8 ft) 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. 41)
Attachment of Vent Pipe
1. Determine vent pipe diameter and maximum pipe lengths
Using Table 11.
NOTE: (Direct Vent/2-Pipe ONLY) vent pipe system has the
same diameter and same length as combustion air pipe as
mentioned in section "Assembly of Combustion Air Pipe (Direct
Vent/2-Pipe system ONLY)."
PIPE DIAMETER
TRANSITION IN
VERTICAL SECTION
A93034
COMBUSTION – AIR
INTAKE HOUSING
3/8 ID TUBE
3/16
DRILL
4"MIN
(102 mm)
TRAP
TO OPEN
DRAIN
Fig. 40 - - Air Intake Housing Plug Fitting Drain
NOTE: Do not count elbows or pipe sections in terminations or
within furnace (all elbows shown in Fig. 42 and Fig. 43 are not
be counted).
2. Determine location of vent pipe connection to inducer
housing as shown in Fig. 35 for application.
3. Reposition elastomeric (rubber) inducer housing outlet cap
and clamp to appropriate unused inducer housing
connection. Tighten clamp.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit
component damage.
Inducer housing outlet cap must be installed and fully seated
against inducer housing. Clamp must be tightened to prevent
any condensate leakage.
4. Install pipe support (factory-supplied in loose parts bag)
into selected furnace casing vent pipe hole. Pipe support
should be positioned at bottom of casing hole.
5. Be certain that mating surfaces of inducer housing
connection elastomeric (rubber) coupling, and 2-in. (51
mm) diameter vent pipe are clean and dry. Assemble the
elastomeric (rubber) vent coupling (with 2 loose clamps)
onto inducer housing connection. Insert the 2-in. (51 mm)
diameter vent pipe through the elastomeric (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. pipe to
inducer housing. Tighten the clamp screws to 15-in-lb. of
torque.
NOTE: Starting at furnace, slope vent pipe a minimum of 1/4-in.
(6 mm) per linear ft with no sags between hangers.
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 internal stop. Clamp must be tightened to prevent
any condensate leakage.
6. Install casing hole filler cap (factory-supplied in loose
parts bag) in unused vent pipe casing hole.
- - 43 - -
BURNER
BOX
COMBUSTION-AIR
PIPE (DIRECT
VENT/2 PIPE)
COMBUSTION-AIR
PIPE (NON-DIRECT
VENT/1-PIPE)
A05093