Bryant 352MAV Installation, Start-Up, And Operating Instructions Manual page 25

Furnace combustion-air and vent pipe connections must be at-
tached as shown in Fig. 34. Combustion-air intake plug fitting and
inducer housing alternate vent cap may need to be relocated in
some applications.
NOTE: Slope combustion-air and vent pipes a minimum of 1/4
in. per linear ft with no sags between hangers.
CAUTION: When combustion-air pipe is installed
above a suspended ceiling, pipe must be insulated with
3/8-in. thick Armaflex-type insulation. Combustion-air
pipe should also be insulated when it passes through
warm, humid space.
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An abandoned masonry chimney may be used as a raceway for
properly insulated and supported combustion-air and vent pipes.
Each furnace must have its own set of combustion-air and vent
pipes and be terminated individually, as shown in Fig. 43, 44, 45,
46, and 47.
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Other gas appliances with their own venting system may also use
the abandoned chiomney as a raceway providing it is permitted by
local code, the current edition of the National Fuel Gas Code and
the vent or liner manufacturer's installation instructions. Care must
be taken to prevent the exhaust gases from one appliance from
contaminating the combustion air of other gas appliances.
CAUTION: When vent pipe is exposed to temperatures
below freezing, such as when it passes through an
unheated space or when a chimney is used as a raceway,
pipe must be insulated as shown in Table 8 with
Armaflex-type insulation.
NOTE: Select 1 vent pipe connection and
1 combustion-air pipe connection.
AIR
FLOW
COMBUSTION- COMBUSTION-
AIR AIR
VENT
VENT
UPFLOW
COMBUSTION-
AIR
VENT
AIR
FLOW
HORIZONTAL-LEFT DISCHARGE
Fig. 34—Combustion-Air and Vent Pipe Connections
—25—
NOTE: Select 1 vent pipe connection and
1 combustion-air pipe connection.
VENT
VENT
COMBUSTION- COMBUSTION-
AIR AIR
AIR
FLOW
DOWNFLOW
COMBUSTION-
AIR
VENT
AIR
FLOW
HORIZONTAL-RIGHT DISCHARGE
CAUTION: Combustion air must not be taken from
inside structure because inside air is frequently contami-
nated by halogens, which include fluorides, chlorides,
bromides, and iodides. These elements are found in
aerosols, detergents, bleaches, cleaning solvents, salts, air
fresheners, adhesives, paint, and other household prod-
ucts. Locate combustion-air inlet as far as possible from
swimming pool and swimming pool pump house. Exces-
sive exposure to contaminated combustion air will result
in safety and performance related problems.
WARNING: Solvent cements are combustible. Keep
away from heat, sparks, and open flame. Use only in well
ventilated areas. Avoid breathing in vapor or allowing
contact with skin or eyes. Failure to follow this warning
could result in fire, property damage, personal injury, or
death.
WARNING: All combustion-air and vent pipes must be
airtight and watertight. Pipes must also terminate exactly
as shown in Fig. 37, 38, 39, 40, or 41. Failure to follow
this warning could result in property damage, personal
injury, or death.
NOTE: The minimum combustion-air and vent pipe length (each)
for these furnaces is 5 ft. Short pipe lengths (5-8 ft) may discharge
water droplets. These droplets may be undesirable, and a 12-in.
minimum offset pipe section is recommended, as shown in Fig. 35,
to reduce excessive droplets from exiting vent pipe outlet.
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