507762-01
Issue 1907
Page 12 of 46
Bracket
(typical)
Metal
Strap
(typical)
Air
Flow
Internal Brace
(provided with
kit)
Figure 18. Horizontal Suspension Kit
NOTE:
When the furnace is installed on a platform or with
the horizontal suspension kit in a crawlspace, it must be
elevated enough to avoid water damage, accommodate
drain trap and to allow the evaporator coil to drain.
Platform Installation of Horizontal Unit
1. Select location for unit keeping in mind service and
other necessary clearances. See Figure 17.
2. Construct a raised wooden frame and cover frame
with a plywood sheet. If unit is installed above finished
space, fabricate an auxiliary drain pan to be installed
under unit. Set unit in drain pan as shown in Figure
19. Leave 8 inches for service clearance below unit for
condensate trap.
3. Provide a service platform in front of unit. When
installing the unit in a crawl space, a proper support
platform may be created using cement blocks.
4. Route auxiliary drain line so that water draining from
this outlet will be easily noticed by the homeowner.
5. If necessary, run the condensate line into a condensate
pump to meet drain line slope requirements. The
pump must be rated for use with condensing furnaces.
Protect the condensate discharge line from the pump
to the outside to avoid freezing.
6. Continue with exhaust, condensate and intake piping
installation according to instructions.
*Gas connector may be
used for Canadian
by local authority
having jurisdiction.
*GAS CONNECTION
INTAKE PIPE
EXHAUST PIPE
RAISED
PLATFORM
SERVICE PLATFORM
installation if acceptable
Figure 19. Platform Installation
Return air may be brought in only through the end of a
furnace installed in the horizontal position. The furnace
is equipped with a removable bottom panel to facilitate
Filters
This unit is not equipped with a filter or rack. A field-provided
high velocity rated filter is required for the unit to operate
properly. Table 1 lists recommended filter sizes.
A filter must be in place whenever the unit is operating.
Furnace Cabinet
Width
Filter Size
Side Return
Bottom Return
17-1/2”
16 x 25 x 1 (1)
16 x 25 x 1 (1)
21”
20 x 25 x 1 (1)
Table 1.
If a highefficiency filter is being installed as part of this
system to ensure better indoor air quality, the filter must
be properly sized. Highefficiency filters have a higher
static pressure drop than standard efficiency glass/foam
filters. If the pressure drop is too great, system capacity
and performance may be reduced. The pressure drop
may also cause the limit to trip more frequently during
the winter and the indoor coil to freeze in the summer,
resulting in an increase in the number of service calls.
Before using any filter with this system, check the
specifications provided by the filter manufacturer
against the data given in the appropriate Allied Air
Product Specifications bulletin. Additional information
is provided in Service and Application Note ACC002
(August 2000).
IMPORTANT
Duct System
Use industry-approved standards to size and install the
supply and return air duct system. Figure 20 shows the
correct supply and return duct installation. Refer to ACCA
Manual D. This will result in a quiet and low-static system
that has uniform air distribution.
NOTE:
This furnace is not certified for operation in heating
mode (indoor blower operating at selected heating speed)
with an external static pressure which exceeds 0.5 inches
w.c. Operation at these conditions may result in improper
limit operation.
