PRODUCT DESIGN
40
Drain Trap and Lines (90% Furnaces Only)
In horizontal applications the condensate drain trap is se-
cured to the furnace side panel, suspending it below the
furnace. A minimum clearance of 4 3/4" below the furnace
must be provided for the drain trap. Additionally, the appro-
priate downward piping 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, ad-
equate measures must be taken to prevent condensate from
freezing.
NOTE:
The use of insulation and/or heat tape is
recommended. Failure to provide proper condensate drain-
age can result in property damage.
Leveling (90% Furnaces Only)
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 (approxi-
mately 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.
Alternate Vent/Flue and Combustion Air Connections
(90% Furnaces Only)
NOTE:
Alternate combustion fresh air inlet location on the
right hand panel side of 90% furnace models has been
discontinued since November 2005.
In horizontal installations provisions for alternate flue and
combustion air piping are available for upflow furnaces with
left discharge. In these positions the flue and combustion
air piping can be run vertically through the side of the fur-
nace. Refer to the following figure "Recommended Installa-
tion Positions" for further detail. The standard piping con-
nections may also be used in these positions. Refer to
Vent/
Flue Pipe and Combustion Air Pipe
section in this manual
or the installation instructions for details concerning the con-
version to the alternate vent/flue and combustion air con-
nections on the 90% furnace.
AIR
DISCHARGE
AIR
DISCHARGE
AIR
DISCHARGE
Bottom
Return
Duct
Connection
Bottom
Return
Duct
Connection
Bottom
Return
Duct
Connection
Side
Return
Duct
Connection
Side
Return
Duct
Connection
UPFLOW
UPRIGHT
UPFLOW HORIZONTAL
RIGHT AIR DISCHARGE
UPFLOW HORIZONTAL
LEFT AIR DISCHARGE
ALTERNATE FLUE AND
COMBUSTION AIR PIPE
LOCATIONS
ALTERNATE FLUE AND
COMBUSTION AIR PIPE
LOCATIONS
AIR
DISCHARGE
AIR
DISCHARGE
AIR
DISCHARGE
Bottom
Return
Duct
Connection
Bottom
Return
Duct
Connection
Bottom
Return
Duct
Connection
COUNTERFLOW
UPRIGHT
COUNTERFLOW HORIZONTAL
RIGHT AIR DISCHARGE
COUNTERFLOW HORIZONTAL
LEFT AIR DISCHARGE
ALTERNATE FLUE AND
COMBUSTION AIR PIPE
LOCATIONS
ALTERNATE FLUE AND
COMBUSTION AIR PIPE
LOCATIONS
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 connec-
tions
Alternate Electrical and Gas Line Connections
The 80% & 90% furnaces have provisions allowing for elec-
trical and gas line connections through either side panel. In
horizontal applications the connections can be made either
through the “top” or “bottom” of the furnace.
Drain Pan (90% Furnaces Only)
A drain pan must be provided if the furnace is installed above
a conditioned area. The drain pan must cover the entire area
under the furnace (and air conditioning coil if applicable).
Freeze Protection (90% Furnaces Only)
If the drain trap and drain line will be exposed to tempera-
tures near or below freezing, adequate measures must be
taken to prevent condensate from freezing.
NOTE:
The use
of insulation and/or heat tape is recommended. Failure to
provide proper condensate drainage can result in property
damage.