9
H
ORIZONTAL
A
PPLICATIONS
& C
ONSIDERATIONS
When installing a furnace horizontally, additional consideration
must be given to the following:
F
URNACE
S
USPENSION
If suspending the furnace from rafters or joists, use 3/8" threaded
rod and 2”x2”x1/8” angle iron as shown in the following dia-
gram. The length of rod will depend on the application and the
clearances necessary.
If the furnace is installed in a crawl space it must be suspended
from the floor joist or supported by a concrete pad. Never install
the furnace on the ground or allow it to be exposed to water.
2" 2" 3/8"
ANGLE
IRON
(3
PLACES
)
X
X
Figure 2
F
RONT
C
OVER
P
RESSURE
S
WITCH
T
UBE
L
OCATION
When an upflow model is installed horizontally with left side
down or a counterflow model is installed horizontally with
right side down, the front cover pressure switch tube must
be re-located to the lower port of the collector box cover.
1. Remove tube from front cover pressure switch and
collector box cover.
2. Remove rubber plug from bottom collector box port
and install on top collector box port.
3. Locate 24” x 1/4” tube in parts bag.
4. Install one end on front cover pressure switch.
5. Route tube to lower port on collector box cover and
cut off excess tubing.
D
RAIN
T
RAP
AND
L
INES
In horizontal applications the condensate drain trap is secured to
the furnace side panel, suspending it below the furnace. A mini-
mum clearance of 5.5” below the furnace must be provided for
the drain trap. Additionally, the appropriate downward piping
slope must be maintained from the drain trap to the drain loca-
tion. Refer to
Condensate Drain Trap and Lines
for further de-
tails. 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.
L
EVELING
Leveling ensures proper condensate drainage from the heat ex-
changer and induced draft blower. For proper flue pipe drainage,
the furnace must be level lengthwise from end to end. The
furnace should have a slight tilt from back to front with the
access doors downhill from the back panel approximately 1/2
to 3/4 inches. The slight tilt allows the heat exchanger conden-
sate, generated in the recuperator coil, to flow forward to the
recuperator coil front cover.
A
LTERNATE
V
ENT
/F
LUE
AND
C
OMBUSTION
A
IR
C
ONNECTIONS
In horizontal installations provisions for alternate flue and com-
bustion air piping are available for upflow furnaces with left dis-
charge and counterflow furnaces with right air discharge. This
configuration allows the flue and combustion air piping to be run
vertically through the side of the furnace. Refer to the “Recom-
mended Installation Positions” figure for further detail. The stan-
dard piping connections may also be used in these positions.
Refer to
Vent/Flue Pipe and Combustion Air Pipe
for details con-
cerning the conversion to the alternate vent/flue and combus-
tion air connections.
When using the horizontal alternate vent configuration, you must
use the RF000142 vent drain kit. See following illustration.
Alternate Vent/Flue Location
Figure 3A
