18-CD34D1-5-EN 7
INSTALLER’S GUIDE
UPFLOW INSTALLATION
The coil is always placed downstream of the furnace airflow.
Apply gasket material (duct seal field supplied) to ALL mating
surfaces between the furnace and the coil case.
NOTE: The top flanges on the furnace must be bent
90 degrees upward to allow the coil attachment.
UPFLO
W
FURNA
CE
CASED
COIL
1
VERTICAL
INSTALLATIONS:
Seal with field
supplied sealant
or gasket
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.
2
Required floor opening: (DOWNFLOW)
Figure 3 and Table 1
CABINET
WIDTH
RETURN
DUCT
WIDTH
FLOOR OPENING PLENUM OPENING
"A"
"B"
"C"
"D"
14-1/2"
13-1/4"
13-5/8"
20-1/8"
12-5/8"
19-3/8"
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. Three brackets (with screws) are included
with downflow furnaces for installation to 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. 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,
CASED COIL CONNECTION
BRACKET FOR DOWNFLOW
FURNACE IN HORIZONTAL
DOWNFLOW ONLY
4
converted to horizontal, aligns and attaches the coil as in Figure 1.
However, the coil requires additional support. This furnace may
be installed in an attic or crawl space in the horizontal position by
placing the furnace on the left or right side (as viewed from the
front in the upright 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 Clearance Table on Outline Drawings and
Figure 5).
