to attach any portion of return-air duct. Bypass humidifier connec-
tions should be made at ductwork or coil casing sides exterior to
furnace.
Step 5—Downflow Installation
NOTE: This furnace is approved for use on combustible materials
or wood flooring. A factory accessory floor base, as listed on the
furnace rating plate, MUST be used. A factory accessory floor
base is not required when this furnace is installed on manufactur-
er’s Coil Assembly Part No. CD5 or CK5, or Coil Box Part No.
KCAKC is used.
1. Determine application being installed from Table 3.
2. Construct hole in floor per dimensions specified in Table 3
and Fig. 5.
3. Construct plenum to dimensions specified in Table 3.
4. If downflow subbase (KGASB) is used, install as shown in
Fig. 6.
If coil assembly CD5, CK5, or Coil Box KCAKC is used,
install as shown in Fig. 7.
Step 6—Horizontal Attic Installation
Do not install the furnace on its back; safety control operation
will be adversely affected. Never connect return-air ducts to
the sides or back of the furnace. Failure to follow this warning
could result in fire, personal injury, or death.
The furnace can be installed horizontally on either the left-hand
(LH) or right-hand (RH) side. A typical attic installation is shown
in Fig. 8.
CONSTRUCT A WORKING PLATFORM
Construct working platform on location where all required furnace
clearances are met. (See Fig. 2 and 8.)
Table 3—Opening Dimensions (In.)
FURNACE
CASING
WIDTH
APPLICATION
PLENUM OPENING FLOOR OPENING
ABCD
14-3/16
Non-Combustible Flooring 12-11/16 19 13-3/8 19-5/8
Combustible Flooring Using KGASB Subbase 11-13/16 19 13-7/16 20-3/8
Combustible Flooring with CD5 or CK5 Coil Assembly or
KCAKC Coil Box
12-5/16 19 13-5/16 20
17-1/2
Non-Combustible Flooring 16 19 16-5/8 19-5/8
Combustible Flooring Using KGASB Subbase 15-1/8 19 16-3/4 20-3/8
Combustible Flooring with CD5 or CK5 Coil Assembly or
KCAKC Coil Box
15-1/2 19 16-1/2 20
21
Non-Combustible Flooring 19-1/2 19 20-1/8 19-5/8
Combustible Flooring Using KGASB Subbase 18-5/8 19 20-1/4 20-3/8
Combustible Flooring with CD5 or CK5 Coil Assembly or
KCAKC Coil Box
19 19 20 20
24-1/2
Non-Combustible Flooring 23 19 23-5/8 19-5/8
Combustible Flooring Using KGASB Subbase 22-1/8 19 23-3/4 20-3/8
Combustible Flooring with CD5 or CK5 Coil Assembly or
KCAKC Coil Box
22-1/2 19 23-1/2 20
Fig. 5—Floor and Plenum Opening Dimensions
A96283
PLENUM
OPENING
C
A
B
D
FLOOR
OPENING
7
