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*MEC96 models may be installed upflow or horizontally
with left or right side down. *CEC96 models may be
installed down flow or horizontally with left or right side
down. Do not install this furnace on its back. For
upright
upflow
furnaces, return air ductwork may be attached to
the side panel(s) and/or basepan. For
horizontal upflow
furnaces, return air ductwork must be attached to the
basepan. For both
upright or horizontal counterflow
furnaces
,
return ductwork must be attached to the basepan
(top end of the blower compartment).
NOTE:
Ductwork
must never be attached to the back of the furnace.
Refer to “Recommended Installation Positions” figure for
appropriate installation positions, ductwork connections,
and resulting airflow arrangements.
HORIZONTAL APPLICATIONS
& CONSIDERATIONS
When installing a furnace horizontally, additional
consideration must be given to the following:
Furnace Suspension
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 diagram. 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 3
Front Cover Pressure Switch Tube Location
When a furnace is installed horizontally with left side down,
the front cover pressure switch tube must be re-located to
he 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 of collector box port.
3. Locate 24’’ x 1/4’’ tube in bag assembly.
4. Install one end on front cover pressure switch.
5. Route tube to lower port on collector box cover and
cut off excess tubing.
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 piping slope must be maintained
from the drain trap to the drain location. Refer to
Condensate Drain Trap and Lines
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.
Horizontal Furnace Leveling
Leveling ensures proper condensate drainage from
the heat exchanger. 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
condensate, generated in the recuperator coil, to flow
forward to the recuperator coil front cover.
Alternate Electrical and Gas Line Connections
This furnace has provisions allowing for electrical 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
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
Refer to
Horizontal Applications and Conditions - Drain
Trap and Lines.
PROPANE GAS/HIGH ALTITUDE
INSTALLATIONS
WARNING
Possible property damage, personal injury or death may
occur if the correct conversion kits are not installed. The
appropriate kits must be applied to ensure safe and proper
furnace operation. All conversions must be performed by a
qualified installer or service agency.
This furnace is shipped from the factory configured for
natural gas at standard altitude. Propane gas installations
require an orifice and spring change to compensate for the
energy content difference between natural and propane
gas.
