Bryant 355CAV - Manual (Page 39)

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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.
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
conditioning 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. 36 or in Fig. 37 per application in outside
ambient by insulating pipe as indicated in Table 6.
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
furnace 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 6.
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 8. There are four options of vent/combustion air termination
kits available as shown in Table 8.
NOTE: Combustion air pipe must have the same diameter as vent
pipe.
Concentric Vent / Combustion Air Termination Kit
(Direct Vent / 2--Pipe System Only
Determine an appropriate location for termination kit using the
guidelines provided in section “Vent Termination: General” 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.
Roof terminations--Locate assembly through roof to
appropriate height as shown in Fig. 36 or Fig. 37.
Sidewall terminations--Locate assembly through sidewall
with rain shield positioned no more than 1--in (25 mm). from
wall as shown in Fig. 36 and Fig. 37.
4. Disassemble loose pipe fittings. Clean and cement using
same procedures as used for system piping.
5. Check required dimensions as shown.
Two--Pipe Termination Kit (Direct Vent / 2--Pipe
System Only)
Determine an appropriate location for termination kit using the
guidelines provided in section “Vent Termination: General” in this
instruction.
1. Cut 2 holes, 1 for each pipe, of appropriate size for pipe size
being used.
2. Loosely install elbow in bracket and place assembly on
combustion--air pipe.
Roof terminations--Loosely install pipe coupling on
properly cut vent pipe. Coupling must be positioned so
bracket will mount as shown in Fig. 38.
For applications using combustion--air pipe option,
indicated by dashed lines in Fig. 36, install 90_ street elbow
into 90_ elbow, making a U--fitting. A 180_ U--fitting may
be used.
Sidewall terminations--Install bracket as shown in Fig. 36.
For applications using vent pipe option indicated by dashed lines
in Fig. 36, rotate vent elbow 90_ from position shown in Fig. 36.
3. Disassemble loose pipe fittings. Clean and cement using
same procedures as used for system piping.
4. Check required dimensions as shown in Fig. 36.
(Direct Vent / 2--Pipe System ONLY)--When 2 or more 355CAV
furnaces are vented near each other, 2 vent terminations may be
installed as shown in Fig. 36, but next vent termination must be at
least 36 in. (914 mm) away from first 2 terminations. It is
important that vent terminations be made as shown in Fig. 36 to
avoid recirculation of flue gases.
355C
A
V
355C
A
V