Carrier 58MXA - Page 15

NOTE: Remove furnace perforated, discharge duct flanges when
they interfere with mating flanges on coil on downflow subbase.
To remove furnace perforated, discharge duct flange, use wide
duct pliers or duct flange tool or hand seamers to bend flange back
and forth until it breaks off. Be careful of sharp edges. (See Fig.
21.)
Table 1—Opening Dimensions (in.)
FURNACE
CASING
WIDTH
APPLICATION
PLENUM OPENING FLOOR OPENING
ABCD
17-1/2
Upflow Applications 16 24–1/8 16–5/8 24–3/4
Downflow Applications on Non-Combustible Flooring 15-7/8 19 16-1/2 19-5/8
Downflow Applications on Combustible Flooring Using
KGASB Subbase
Furnace with or without CD5 or CK5 Coil Assembly or
KCAKC Coil Box
15-1/8 19 16-3/4 20-3/8
Downflow Applications on Combustible Flooring NOT Using
KGASB Subbase
Furnace with or without CD5 or CK5 Coil Assembly or
KCAKC Coil Box
15-1/2 19 16-1/2 20
21
Upflow Applications 19-1/2 24-1/8 20-1/8 24-3/4
Downflow Applications on Non-Combustible Flooring 19-3/8 19 20 19-5/8
Downflow Applications on Combustible Flooring Using
KGASB Subbase
Furnace with or without CD5 or CK5 Coil Assembly or
KCAKC Coil Box
18-5/8 19 20-1/4 20-3/8
Downflow Applications on Combustible Flooring NOT Using
KGASB Subbase
Furnace with or without CD5 or CK5 Coil Assembly or
KCAKC Coil Box
19 19 20 20
24-1/2
Upflow Applications 23 24-1/8 23-5/8 24-3/4
Downflow Applications on Non-Combustible Flooring 22-7/8 19 23-1/2 19-5/8
Downflow Applications on Combustible Flooring Using
KGASB Subbase
Furnace with or without CD5 or CK5 Coil Assembly or
KCAKC Coil Box
22-1/8 19 23-3/4 20-3/8
Downflow Applications on Combustible Flooring NOT Using
KGASB Subbase
Furnace with or without CD5 or CK5 Coil Assembly or
KCAKC Coil Box
22-1/2 19 23-1/2 20
Fig. 18—Floor and Plenum Opening Dimensions
A96283
PLENUM
OPENING
C
A
B
D
FLOOR
OPENING
Fig. 19—Furnace, Plenum, and Subbase Installed
on a Combustible Floor
A96285
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
FLOOR
OPENING
FURNACE
(OR COIL CASING
WHEN USED)
COMBUSTIBLE
FLOORING
15