Bryant 345MAV User Manual

Page 18

DOWNFLOW FURNACES

Connect supply-air duct to supply-air opening on furnace. The
supply-air duct attachment must ONLY be connected to furnace
supply/outlet or air conditioning coil casing (when used), when
installed on non-combustible material. When installed on combus-
tible material, supply-air duct attachment must ONLY be con-
nected to an accessory subbase or factory approved air condition-
ing coil casing. DO NOT cut main furnace casing to attach supply
side air duct, humidifier, or other accessories. All accessories
MUST be connected external to furnace main casing.

HORIZONTAL FURNACES

Connect supply-air duct to supply air opening on furnace. The
supply-air duct attachment must ONLY be connected to furnace
supply/outlet or air conditioning coil casing (when used). DO NOT
cut main furnace casing to attach supply side air duct, humidifier,
or other accessories. All accessories MUST be connected external
to furnace main casing.

Return Air Connections

The furnace and its return air system shall be designed and
installed so that negative pressure created by the air ciculating fan
cannot affect another appliance’s combustion air supply or act to
mix products of combustion with circulating air, and that the air
circulating fan of the furnace, if installed in an enclosure commu-
nicating with another fuel-burning appliance not of the direct-vent
type, shall be operable only when any door or panel covering an
opening in the furnace fan compartment or in a return air plenum
on ducts is in the closed position.

WARNING:

Never connect return-air ducts to the back

of the furnace. Return-air duct connections on furnace
side(s) permitted in upflow applications only. A failure to
follow this warning could result in fire, personal injury, or
death.

UPFLOW FURNACES

The return-air duct must be connected to bottom, sides (left or
right), or a combination of bottom and side(s) of main furnace
casing as shown in Fig. 2. Bypass humidifier may be attached into
unused side return air portion of the furnace casing. DO NOT
connect any portion of return-air duct to back of furnace casing.

DOWNFLOW AND HORIZONTAL FURNACES

The return-air duct must be connected to return-air opening
provided as shown in Fig. 2. DO NOT cut into casing sides or back
to attach any portion of return-air duct. Bypass humidifier connec-
tions should be made at ductwork or coil casing sides exterior to
furnace.

Filter Arrangement

CAUTION:

Never operate unit without a filter or with

blower access panel removed. Failure to follow this
caution wil result in intermittent unit operation or perfor-
mance satisfaction.

Fig. 24—Crawlspace Horizontal Application

A96209

NOTES:

ANGLE
IRON OR
EQUIVALENT

(B)

(A) ROD LOCATION

USING DIMPLE
LOCATORS
(SEE DIMENSIONAL
DWG FOR
LOCATIONS)

-IN. MAX

ALTERNATE SUPPORT
LOCATION FROM BACK

ALTERNATE SUPPORT
LOCATION 4-IN. MIN
8-IN. MAX

A 3-IN. MINIMUM

CLEARANCE TO

COMBUSTION-AIR INTAKE

IS REQUIRED.

⁄

-IN. ROD

(A)

(B)

(A)

(B)

(A)

1. A 1 In. clearance minimum between top of

furnace and combustible material.

2. The entire length of furnace must be

supported when furnace is used in
horizontal position to ensure proper
drainage.

3. Bottom side combustion-air entry cannot

be used when furnace is installed with
hangers as shown.

(A) PREFERRED ROD LOCATION

(B) ALTERNATE ROD LOCATION

DRAIN

⁄

″

-IN. HEX NUT

& WASHER (4)

REQD PER ROD

VENT

COMBUSTION-AIR

INTAKE

—18—