Bryant 355MAV EN User Manual

Page 22

CAUTION:

Combustion air must not be taken from

inside structure because that 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.
Excessive 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. 31, 32, 33, 34, or 35. 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. 29,
to reduce excessive droplets from exiting vent pipe outlet.

Combustion-Air and Vent Pipe Diameter

Determine combustion-air and vent pipe diameter.

1. Using Table 6, individually determine the combustion-air

and vent pipe diameters. Pick the larger of these 2 pipe
diameters and use this diameter for both combustion-air and
vent pipes.

2. When installing vent systems of short pipe length, use the

smallest allowable pipe diameter. Do not use pipe size
greater than required or incomplete combustion, flame
disturbance, or flame sense lockout may occur.

NOTE:

Do not count elbows or pipe sections in terminations or

within furnace. See shaded areas in Fig. 31, 32, 33, 34, and 35.

TABLE 5—COMBUSTION-AIR AND VENT PIPE

TERMINATION CLEARANCES

LOCATION

CLEARANCE (FT)

U.S.A.

Canada

Above grade level or above antici-
pated snow depth

1†

Dryer vent

From plumbing vent stack

From any mechanical fresh air intake

For furnaces with an input capacity
less than 100,000 Btuh—from any
non-mechanical air supply (windows
or doors which can be opened) or
combustion-air opening

For furnaces with an input capacity
greater than 100,000 Btuh—from any
non-mechanical air supply (windows
or doors which can be opened) or
combustion-air opening

From service regulator vent, electric
and gas meters, and relief equipment

6‡

Above grade when adjacent to public
walkway

* Horizontal distance.
† 18 in. above roof surface in Canada.
‡ 36 in. to electric meter in Canada only.
NOTES:
1. If installing 2 adjacent 355MAV Furnaces, refer to Multiventing and Vent

Terminations section for proper vent configurations.

2. When locating combustion-air and vent terminations, consideration must be

given to prevailing winds, location, and other conditions which may cause
recirculation of the appliance’s own flue products or the flue products of
adjacent vents. Recirculation can cause poor combustion, inlet condensate
problems, and accelerated corrosion of heat exchangers.

Fig. 27—Combustion-Air and Vent Pipe Diameter

Transition Location and Elbow Configuration

A93034

FURNACE

PIPE DIAMETER

TRANSITION IN

VERTICAL SECTION

NOT IN
HORIZONTAL
SECTION

Fig. 28—Combustion-Air and Vent Pipe Connections

A96187

COMBUSTION-

AIR

COMBUSTION-

AIR

FLOW

VENT

AIR

FLOW

AIR

FLOW

AIR

FLOW

UPFLOW

DOWNFLOW

HORIZONTAL-LEFT DISCHARGE

HORIZONTAL-RIGHT DISCHARGE

Select 1 vent pipe connection and
1 combustion-air pipe connection.

COMBUSTION-

AIR

COMBUSTION-

AIR

COMBUSTION-

AIR

COMBUSTION-

AIR

VENT

NOTE:

Select 1 vent pipe connection and
1 combustion-air pipe connection.

NOTE:

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