PRODUCT DESIGN
35
Rev. 0
closed
non-direct vent furnace has an adequate sup-
ply of combustion air, vent from a nearby uncontami-
nated room or from outdoors. Refer to the
Combus-
tion and Ventilation Air Requirements section for de-
tails.
•
If the furnace is used in connection with a cooling
unit, install the furnace upstream or in parallel with
the cooling unit. Premature heat exchanger failure
will result if the cooling unit is placed ahead of the
furnace.
•
If the furnace is installed in a residential garage, po-
sition the furnace so that the burners and ignition
source are located not less than 18 inches (457 mm)
above the floor. Protect the furnace from physical
damage by vehicles.
•
If the furnace is installed horizontally, the furnace
access doors must be vertical so that the burners
fire horizontally into the heat exchanger. Do not in-
stall the unit with the access doors on the “up/top” or
“down/bottom” side of the furnace.
Clearances and Accessibility
Installations must adhere to the clearances to combustible
materials which this furnace has been design certified to.
The minimum clearance information for this furnace is pro-
vided on the unit’s clearance label. These clearances must
be permanently maintained. Clearances must also accom-
modate an installation’s gas, electrical, and drain trap and
drain line connections. If the alternate combustion air in-
take or vent/flue connections are used additional clearances
must be provided to accommodate these connections. Refer
to
Vent Flue Pipe and Combustion Air Pipe section for de-
tails. Note: In addition to the required clearances to com-
bustible materials, a minimum of 36 inches service clear-
ance must be available in front of the unit.
TOP
BOTTOM
SIDE
SIDE
SIDE
TOP
BOTTOM
Upflow Counterflow Horizontal
A furnace installed in a confined space (i.e., a closet or
utility room) must have two ventilation openings with a total
minimum free area of 0.25 square inches per 1,000 BTU/
hr of furnace input rating. Refer to the
PRODUCT IDENTI-
FICATION section, pages 7 and 8, for minimum clearances
to combustible materials dimensions. One of the ventila-
tion openings must be within 12 inches of the top; the other
opening must be within 12 inches of the bottom of the con-
fined space. In a typical construction, the clearance be-
tween the door and door frame is usually adequate to sat-
isfy this ventilation requirement.
Furnace Suspension
If suspending the furnace from rafters or joist, use 3/8"
threaded rod and 2”x2”x1/8” angle iron as shown below.
The length of rod will depend on the application and the
clearances necessary.
TILT OUTWARD TO ALLOW FOR
DOOR AND CIRCULATOR BLOWER
REMOVAL
3/8" DIAMETER
THREADED ROD
(6 PLACES)
PROVIDE 8" MINMUM CLEARANCE BETWEEN
CENTER ROD AND FURNACE CABINET
TO ALLOW FOR CIRCULATOR BLOWER REMOVAL
ASSURE FURNACE IS LEVEL FROM
END TO END AND HAS A SLIGHT
FORWARD TILT WITH THE FRONT
OF THE FURNACE 0"-3/4"
BELOW THE BACK OF THE FURNACE
POSITION AS CLOSE AS POSSIBLE
TO BLOWER DECK TO ALLOW FOR
CIRCULATOR BLOWER REMOVAL
2"X2"X1/8"
ANGLE IRON
(3 PLACES)
HOLD DOWN
NUTS
SUPPORT
NUTS
Suspended Furnace
Horizontal Applications and Considerations
General
Horizontal applications, in particular, may dictate many of
the installation’s specifics such as airflow direction, duct-
work connections, flue and combustion air pipe connec-
tions, etc. The basic application of this furnace as a hori-
zontal furnace differs only slightly from an upright installa-
tion. When installing a furnace horizontally, additional con-
sideration must be given to the following:
ALTERNATE VENT/FLUE
AND COMBUSTION AIR
INTAKE LOCATIONS
FURNACE MUST BE LEVEL
FROM END TO END
FURNACE MUST BE LEVEL
OR SLIGHTLY TILTED FORWARD
WITH THE DOORS 0" - 3/4"
BELOW THE BACK PANEL
DRAIN LINE WITH 1/4" PER FOOT
DOWNWARD SLOPE
36" MINIMUM SERVICE
CLEARANCE REQUIRED
FURNACE MUST BE SUPPORTED
AT BOTH ENDS AND MIDDLE
DRAIN PAN
GAS LINE WITH
DRIP LEG (3" MINIMUM)
4 3/4" MINIMUM
DRAIN TRAP
CLEARANCE
Horizontal Furnace