Installation; Leveling Legs (If Desired); Upflow - Bryant 345MAV Installation, Start-Up, And Operating Instructions Manual

SUPPLY
AIR
INTERIOR
HEATED
SPACE
RETURN AIR
* Minimum opening size is 100 sq. in. with
minimum dimensions of 3-In.
NOTE: Side clearance required as needed for
combustion-air pipe and termination,
vent pipe, and gas and electrical connections.
Fig. 17—Confined Space: Air for Combustion and
Ventilation from an Unconfined Space
2. If combustion air is taken from outdoors through horizontal
ducts, the openings and ducts MUST have at least 1 sq in.
of free area per 2000 Btuh of the total input for all
equipment within the confined space. (See Fig. 18.)
For Example:
COMBUSTION AIR FROM OUTDOORS THROUGH
HORIZONTAL DUCTS
345MAV Furnace Free Area per Opening
Input Btuh
40,000
60,000
80,000
100,000
120,000
3. When ducts are used, they must be of the same cross-
sectional area as the free area of the openings to which they
connect. The minimum dimension of ducts must not be less
than 3 in. (See Fig. 18.)

INSTALLATION

I. LEVELING LEGS (IF DESIRED)
When furnace is used in upflow position with side inlet(s), leveling
legs may be desired. (See Fig. 19.) Install field-supplied,
corrosion-resistant 5/16-in. machine bolts and nuts.
VENT THROUGH ROOF
OR SIDEWALL
12 MAX
1 SQ IN.
PER 1000
BTUH * IN DOOR
OR WALL
UNCONFINED
SPACE
3 MIN
(FRONT)
1 SQ IN.
PER 1000
BTUH * IN DOOR
OR WALL
12 MAX
A96185
Round Pipe
(Sq In.) (In. Dia)
20.0 6
30.0 7
40.0 8
50.0 8
60.0 9
NOTE: The maximum length of bolt should not exceed 1-1/2 in.
DUCTS
OUTDOORS
12 MAX
1 SQ IN.
PER 2000
A
SUPPLY
BTUH *
DUCTS
TO
OUTDOORS
1 SQ IN.
PER 2000
B
BTUH *
12 MAX
RETURN AIR
* Minimum dimensions of 3-In.
NOTES: 1. Use any of the following
combinations of openings:
A & B C & D
2. Side clearance required as needed for
combustion-air pipe and termination,
vent pipe, and gas and electrical connections.
Fig. 18—Confined Space: Air for Combustion and
Ventilation from Outdoors
5
⁄
16
3
1 ⁄
4
5
⁄
16
—15—
1 SQ IN.
PER 4000
BTUH *
TO
D
VENT
THROUGH
F
ROOF
AIR
OR
SIDEWALL
E
G
C
12 MAX
DUCT
1 SQ IN.
TO
PER 4000
OUTDOORS
BTUH *
D & E F & G
5
⁄
16
3
1 ⁄
4
5
⁄
16
3
1 ⁄
4
3
1 ⁄
4
Fig. 19—Leveling Legs
12
MAX
1 SQ IN.
PER 4000
BTUH *
1 SQ IN.
PER 4000
BTUH *
12
MAX
A96186
A89014