18-CD35D1-1 7
INSTALLER’S GUIDE
UPFLOW INSTALLATION
The cased coil must be secured to the furnace and both the
furnace and the cased coil must be properly supported.
The coil is always placed downstream of the furnace airflow.
DOWNFLOW INSTALLATION
▲
WARNING
!
Do NOT install the furnace directly on carpeting,
tile or other combustible material other than
wood flooring. For vertical downflow application,
subbase (BAYBASE205) must be used between
the furnace and combustible flooring. When the
downflow furnace is installed vertically with a
cased coil, a subbase is not required.
Required floor opening:
SUBBASE CROSS SECTION
2
TABLE 1
CABINET
WIDTH
RETURN
DUCT
WIDTH
FLOOR OPENING PLENUM OPENING
"A"
"B"
"C"
"D"
17-1/2"
16-1/4"
16-5/8"
20-1/8"
15-5/8"
19-3/8"
21"
19-3/4"
20-1/8"
20-1/8"
19-1/8"
19-3/8"
24-1/2"
23-1/4"
23-5/8"
20-1/8"
22-5/8"
19-3/8"
FURNACE
FRONT
A (width)
B (depth)
C
D
3
HORIZONTAL INSTALLATION
The coil and furnace must be fully supported when used in the
horizontal position. It is always recommended that an auxiliary
drain pan be installed under a horizontally installed evaporator
coil or 95% gas furnace. Connect the auxiliary drain line to a
separate drain line (no trap is needed in this line).
Installing the three brackets (with screws) that are included in
donwflow furnaces will stabilize and secure the furnace and
cased coil in the horizontal position. See Figure 4.
IMPORTANT: The cased coil must be placed
downstream of the furnace. In horizontal
installations, the apex of the coil may point
either toward or away from the furnace. See the
coil Installer's Guide for more details.
The cased coil is secured to the furnace and both the furnace and
the cased coil must be properly supported. If used, the brackets
mount using the rear screws on the coil case and use the screws
provided to secure the bracket to the furnace. The remaining
bracket is placed as close to center as possible (horizontally)
between the coil case front and the furnace bottom channel (for
downflow/horizontal furnace). Use four of the screws provided to
secure the bracket. The upflow furnace, converted to horizontal,
aligns and attaches the coil as in Figure 1. However, the coil
requires additional support.
DOWNFLOW ONLY
CASED COIL CONNECTION
BRACKET FOR DOWNFLOW
FURNACE IN HORIZONTAL
4
The furnace may be installed in an attic or crawl space in the
horizontal position by placing the furnace on the left side (as
viewed from the front in the vertical position). The horizontal
furnace installation in an attic should be on a service platform
large enough to allow for proper clearances on all sides and
service access to the front of the furnace (See Figure 3 and Table
1). Line contact is only permissible between lines formed by
intersections of the top and two sides of the furnace casing and
building joists, studs, or framing.
