SYSTEM OPERATION
9
cements and glues
antistatic fabric softeners for clothes dryers
and masonry acid washing materials
β’ Isolate a non-direct vent furnace if it is installed near
an area frequently contaminated by any of the above
substances. This protects the non-direct vent furnace
from airborne contaminants. To ensure that the enclosed
non-direct vent furnace has an adequate supply of
combustion air, vent from a nearby uncontaminated
room or from outdoors. Refer to the Combustion and
Ventilation Air Requirements section in this manual or
the installation instructions for details.
β’ If the furnace is used in connection with a cooling unit,
install the furnace upstream or in parallel with the cooling
unit coil. Premature heat exchanger failure will result
if the cooling unit coil is placed in the return air of the
furnace.
β’ If the furnace is installed in a residential garage, position
the furnace so that the burners and ignition source are
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Protect the furnace from physical damage by vehicles.
β’ If the furnace is installed horizontally, the furnace access
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into the heat exchanger. Do not install the unit with the
access doors on the βup/topβ or βdown/bottomβ side of
the furnace.
β’ ξ²ξξ ξξξξξξξξξξξ ξξξξξξξξξξξξξξξ ξξξξ ξξξξ ξξξξξξξξξξξξξ ξξξξξ
must be downstream on the supply (positive) side of
the furnace heat exchanger.
β’ Counterξow Installation over a noncombustible ξoor.
Before setting the furnace over the plenum opening,
ensure the surface around the opening is smooth and
level. A tight seal should be made between the furnace
ξ
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ξξ ξξξξξξ ξξ ξξξξξξξξξ ξξξ
ξ
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compound or cement grout.
β’ Counterξow Installation over a combustible ξoor. If
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ξξξξ ξξξ ξξξξξξξξξξ ξξξ
ξξ
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applicable for your model for details). A special
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unit installations over any combustible material including
wood. Refer to sub-base instructions for installation
details. Follow the instructions with the sub-base for
proper installation. Do not install the furnace directly
on carpeting, tile, or other combustible material other
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β’ (ξ±ξ²ξ·ξ¨ξ The sub-base will not be required if an air
conditioning coil is installed between the supply air
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POSITION* SIDES REAR FRONT BOTTOM FLUE TOP
Upflo w 0" 0" 1" C 0" 1"
Horizontal 6" 0" 1" C 0" 6"
*M EC96 M INIM UM CLEARANCES TO COMBUSTIBLE MATERIALS
POSITION* SIDES REAR FRONT BOTTOM FLUE TOP
Counterflow 0" 0" 1" NC 0"
Horizontal 6" 0" 1" C 0" 6"
*CEC96 M INIM UM CLEARANCES TO COM BUSTIBLE M ATERIALS
β’ ξ¦ξξ ξξ¬ξξξξξξξξξξξξξξξξ
ξξξξξ
ξξξξξξξξξξξξξξξ°ξΈξΆξ·ξξ
ξξξξξξξξξξξξ
β’ ξ±ξ¦ξξ ξξ©ξξξξξξξξξξξξξξξξξξξξξξξξξξξ
ξξξξξ
ξξξξξξξξξξξξξξξξ€ξξξξξ
ξξξξξ
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ξ
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β’ For servicing or cleaning, a 24β front clearance is recommended.
β’ ξΈξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξξ
clearances than the minimum clearances listed above.
β’ In all cases, accessibility clearance must take precedence over from
the enclosure where accessibility clearances are greater.
β’ Approved for line contact in the horizontal position.
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Installations must adhere to the clearances to combustible
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ξξξξξξξξξξξξξξξξξΏξξξξξξ·ξξξ
minimum clearance information for this furnace is provided
on the unitβs clearance label. These clearances must be
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minimum clearances to combustible materials. Clearances
must also accommodate an installationβs gas, electrical,
and drain trap and drain line connections. If the alternate
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a 90% furnace, additional clearances must be provided to
accommodate these connections. Refer to Vent Flue Pipe and
Combustion Air Pipe section in this manual or the installation
instructions for details. ξ±ξ²ξ·ξ¨ξ In addition to the required
clearances to combustible materials, a minimum of 24 inches
service clearance must be available in front of the unit.
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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. One of the ventilation openings must be
within 12 inches of the top; the other opening must be within
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construction, the clearance between the door and door frame
is usually adequate to satisfy this ventilation requirement.