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810SA/811SA: Installation, Start–Up, Operating and Service and Maintenance Instructions
Roll-Out Protection
Provide a minimum 17-3/4 in. x 22 in. (451 mm x 559 mm) piece of
sheet metal for flame roll-out protection in front of burner area for
furnaces closer than 12 inches (305 mm) above the combustible deck or
suspended furnaces closer than 12 inches (305 mm) to joists. The sheet
metal MUST extend underneath the furnace casing by 1 in. (25 mm)
with the door removed.
The bottom closure panel on furnaces of widths 17-1/2 in. (445 mm) and
larger may be used for flame roll-out protection when bottom of furnace
is used for return air connection. See
roll-out shield.
AIR DUCTS
GENERAL REQUIREMENTS
The duct system should be designed and sized according to accepted
national standards such as those published by: Air Conditioning
Contractors Association (ACCA), Sheet Metal and Air Conditioning
Contractors National Association (SMACNA) or American Society of
Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) or
consult The Air Systems Design Guidelines reference tables available
from your local distributor. The duct system should be sized to handle
the required system design CFM at the design external static pressure.
The furnace airflow rates are provided in
(With Filter).
When a furnace is installed so that the supply ducts carry air circulated
by the furnace to areas outside the space containing the furnace, the
return air shall also be handled by duct(s) sealed to the furnace casing
and terminating outside the space containing the furnace.
Secure ductwork with proper fasteners for type of ductwork used. Seal
supply- and return-duct connections to furnace with code approved tape
or duct sealer.
NOTE: Flexible connections should be used between ductwork and
furnace to prevent transmission of vibration. Ductwork passing through
unconditioned space should be insulated and sealed to enhance system
performance. When air conditioning is used, a vapor barrier is
recommended.
Maintain a 1-in. (25 mm) clearance from combustible materials to
supply air ductwork for a distance of 36 in. (914 mm) horizontally from
the furnace. See NFPA 90B or local code for further requirements.
Ductwork Acoustical Treatment
NOTE: Metal duct systems that do not have a 90 degree elbow and 10
ft. (3 M) of main duct to the first branch take-off may require internal
acoustical lining. As an alternative, fibrous ductwork may be used if
constructed and installed in accordance with the latest edition of
SMACNA construction standard on fibrous glass ducts. Both acoustical
lining and fibrous ductwork shall comply with NFPA 90B as tested by
UL Standard 181 for Class 1 Rigid air ducts.
SUPPLY AIR CONNECTIONS
For a furnace not equipped with a cooling coil, the outlet duct shall be
provided with a removable access panel. This opening shall be
accessible when the furnace is installed and shall be of such a size that
the heat exchanger can be viewed for possible openings using light
assistance or a probe can be inserted for sampling the airstream. The
cover attachment shall prevent leaks.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Fig. 13
for proper orientation of
Table
4-AIR DELIVERY-CFM
Upflow and Horizontal Furnaces
Connect supply-air duct to flanges on furnace supply-air outlet. Bend
flange upward to 90° with wide duct pliers (see
duct must be connected to ONLY the furnace supply-outlet-air duct
flanges or air conditioning coil casing (when used). DO NOT cut main
furnace casing side to attach supply air duct, humidifier, or other
accessories. All accessories MUST be connected to duct external to
furnace main casing.
NOTE: For horizontal applications, the top-most flange may be bent
past 90 degrees to allow the evaporator coil to hang on the flange
temporarily while the remaining attachment and sealing of the coil are
performed.
Downflow Furnaces
Connect supply-air duct to supply-air outlet on furnace. Bend flange
inward past 90° with wide duct pliers (see
must be connected to ONLY the furnace supply outlet or air conditioning
coil casing (when used). When installed on combustible material,
supply-air duct must be connected to ONLY the factory-approved
accessory subbase or a factory- approved air conditioning coil casing.
DO NOT cut main furnace casing to attach supply side air duct,
humidifier, or other accessories. All accessories MUST be connected to
duct external to furnace casing.
Return Air Connections
!
FIRE HAZARD
Failure to follow this warning could cause personal injury, death and/or
property damage.
Never connect return-air ducts to the back of the furnace. Follow
instructions below.
UPFLOW/
HORIZONTAL
Fig. 16 – Duct Flanges
Downflow Furnaces
The return-air duct must be connected to return-air opening bottom inlet
(see
Fig.
17). DO NOT cut into casing sides (left or right). Side opening
is permitted for only upflow and most horizontal furnaces (see
Bypass humidifier connections should be made at ductwork or coil
casing sides exterior to furnace.
11
Fig.
16). The supply-air
Fig.
16). The supply-air duct
CAUTION
DOWNFLOW
A190346
Fig.
18).
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