INSTALLATION CONSIDERATIONS
15
ings where both such openings are used. The separation between ducts
servicing upper and lower combustion 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 manufac
-
ture’s installation instructions.
9.3.8.8
Combustion air intake openings located on the exterior of the
building shall have the lowest side of the combustion air intake openings
located at least 12 in. (300 mm) vertically from the adjoining grade level.
Horizontal Applications and Considerations
Horizontal applications, in particular, may dictate many of
the installation’s specifics such as airflow direction, ductwork
connections, flue and/or combustion air pipe connections, etc.
The basic application of this furnace as a horizontal furnace
differs only slightly from an upright installation. When installing
a furnace horizontally, additional consideration must be given
to the following:
Drain Trap and Lines
In horizontal applications the condensate drain trap is secured
to the furnace side panel, suspending it below the furnace. A
minimum clearance of 5.5" below the furnace must be provided
for the drain trap. Additionally, the appropriate downward pip
-
ing slope must be maintained from the drain trap to the drain
location. Refer to
Condensate Drain Trap and Lines
section in
this manual or the installation instructions for further details. If
the drain trap and drain line will be exposed to temperatures
near or below freezing, adequate measures must be taken to
prevent condensate from freezing.
NOTE:
The use of insu
-
lation and/or heat tape is recommended. Failure to provide
proper condensate drainage can result in property damage.
Leveling
Leveling ensures proper condensate drainage from the heat
exchanger and induced draft blower. For proper flue pipe
drainage, the furnace must be level lengthwise from end to
end. The furnace should also be level from back to front or have
a slight tilt with the access doors downhill (approximately 3/4")
from the back panel. The slight tilt allows the heat exchanger
condensate, generated in the recuperator coil, to flow forward
to the recuperator coil front cover.
In horizontal installations with the furnace laying on the left
hand side, the alternate vent connection may be used. In this
configuration the internal elbow is removed. The standard
piping connections may also be used in these positions. Refer
to
Vent/Flue Pipe and Combustion Air Pipe
section in the
installation instructions for details concerning the conversion
to the alternate vent/flue and combustion air con
nections on
the 90% furnace.
The 34.5" single stage furnace is one of the products in our
newly redesigned line of shorter chassis furnaces. It is avail
-
able in 92% AFUE upflow/horizontal model.
The upflow/horizontal 34.5" single stage furnace is available
in the following models:
DM92SE0403AN
DM92SE0603BN
DM92SE0803BN
DM92SE0804CN
DM92SE0805CN
DM92SE1004CN
DM92SE1005CN
DM92SE1205DN
AIR
DISCHARGE
Bottom
Return
Duct
Connection
Side
Return
Duct
Connection
Side
Return
Duct
Connection
UPFLOW
UPRIGHT
AIR
DISCHARGE
Bottom
Return
Duct
Connection
UPFLOW HORIZONTAL
RIGHT AIR DISCHARGE
UPFLOW HORIZONTAL
LEFT AIR DISCHARGE
AIR
DISCHARGE
AIR
DISCHARGE
Bottom
Return
Duct
Connection
Bottom
Return
Duct
Connection
COUNTERFLOW HORIZONTAL
RIGHT AIR DISCHARGE
COUNTERFLOW HORIZONTAL
LEFT AIR DISCHARGE
90% Furnace Recommended Installation Positions
NOTE:
Alternate "vertical" piping connections can not be
used when an upflow 90% furnace is installed with supply
air discharging to the right or when a counterflow furnace is
installed with supply discharging to the left. In this case, use
the standard flue and combustion air piping connections
Alternate Electrical and Gas Line Connections
Furnaces have provisions allowing for electrical and gas line
connections through either side panel. In horizontal applica
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