Operating instructions

PRODUCT DESIGN
17
burner operation. Means shall be provided to prevent the
main burner form igniting should the louver fail to open dur-
ing burner startup and to shut down the main burner if the
louvers close during burner operation.
9.3.8 Combustion Air Ducts. Combustion air ducts shall
comply with 9.3.8.1 through 9.3.8.8.
9.3.8.1 Ducts shall be constructed of galvanized steel or a
material having equivalent corrosion resistance, strength, and
rigidity.
Exception: Within dwellings units, unobstructed stud and
joist spaces shall not be prohibited from conveying com-
bustion air, provided that not more than one fireblock is
removed.
9.3.8.2 Ducts shall terminate in an unobstructed space, al-
lowing free movement of combustion air to the appliances.
9.3.8.3 Ducts shall serve a single space.
9.3.8.4 Ducts shall not serve both upper and lower combus-
tion air openings where both such openings are used. The
separation between ducts servicing upper and lower com-
bustion air openings shall be maintained to the source of
combustion air.
9.3.8.5 Ducts shall not be screened where terminating in an
attic space.
9.3.8.6 Horizontal upper combustion air ducts shall not slope
downward toward the source of combustion air.
9.3.8.7 The remaining space surrounding a chimney liner,
gas vent, special gas vent, or plastic piping installed within
a masonry, metal, or factory built chimney shall not be used
to supply combustion air.
Exception: Direct vent appliances designed for installation
in a solid fuel-burning fireplace where installed in accordance
with the manufacture’s installation instructions.
9.3.8.8 Combustion air intake openings located on the exte-
rior of the building shall have the lowest side of the combus-
tion air intake openings located at least 12 in. (300 mm)
vertically from the adjoining grade level.
Category I Venting (Vertical Venting)
(80% Furnaces Only)
WARNING
TO PREVENT POSSIBLE PERSONAL INJURY OR DEATH DUE TO
ASPHYXIATION, NON-CONDENSING GAS FIRED WARM AIR FURNACES MUST
BE
C
ATEGORY
I
VENTED.
D
O NOT VENT ANY OF THESE FURNACES USING
CATEGORY III VENTING.
Category I Venting is venting at a non-positive pressure. A
furnace vented as Category I is considered a fan-assisted
appliance and does not have to be "gas tight." NOTE: Single-
Stage and Two-Stage gas furnaces with induced draft blow-
ers draw products of combustion through a heat exchanger
allowing in some instances common venting with natural
draft appliances (i.e. water heaters).
All installations must be vented in accordance with National
Fuel Gas Code NFPA 54/ANSI Z223.1 - latest edition. In
Canada, the furnaces must be vented in accordance with
the National Standard of Canada, CAN/CGA B149.1 and
CAN/CGA B149.2 - latest editions and amendments.
NOTE: The vertical height of the Category I venting system
must be at least as great as the horizontal length of the
venting system.
WARNING
T
O PREVENT POSSIBLE DEATH OR PERSONAL INJURY DUE TO
ASPHYXIATION, COMMON VENTING WITH OTHER MANUFACTURER'S
INDUCED DRAFT APPLIANCES IS NOT ALLOWED.
The minimum vent diameter for the Category I venting sys-
tem is as shown in the following chart:
60 4 Inch
80 4 Inch
100 5 Inch
MODEL
MINIMUM VENT
UPFLOW
Under some conditions, larger vents than those shown above
may be required or allowed.
When an existing furnace is removed from a venting system
serving other appliances, the venting system may be too
large to properly vent the remaining attached appliances.
For complete details refer to Exisiting Furnace Removal sec-
tion of this manual.
When resizing any portion of the common venting system,
use the appropriate table in Appendix G in the latest edition
of the National Fuel Gas Code NFPA 54/ANSI Z223.1.
Upflow or Horizontal units are shipped with the induced
draft blower discharging from the top of the furnace ("Top" is
as viewed for an upflow installation). The induced draft blower
can be rotated 90 degrees for Category I venting. Refer to
the following figure. For horizontal installations, a four inch
single wall pipe can be used to extend the induced draft
blower outlet 1/2” beyond the furnace cabinet. Vent the fur-
nace in accordance with the National Fuel Gas Code NFPA
54/ANSI Z223.1 - latest edition. In Canada, vent the furnace
in accordance with the National Standard of Canada, CAN/
CGA B149.1 and CAN/CGA B149.2 - latest editions and
amendments.
NOTE: This furnace is not design certified to be hori-
zontally vented.