Supply-Air Plenum Installation; Concrete Slab; Combustible Floor - Carrier 58DFA Installation, Start-Up, And Operating Instructions Manual

For Example:
58DFA FURNACE IN- FREE AREA PER
PUT BTUH OPENING (SQ IN.)
66,000
88,000
110,000
132,000
b. If combustion air is taken from the outdoors through
horizontal ducts, the openings and ducts MUST have at
least 1 sq in. of free area per 2000 Btuh of the total input
for all equipment within the confined space.
For Example:
58DFA FURNACE IN- FREE AREA PER
PUT BTUH OPENING (SQ IN.)
66,000
88,000
110,000
132,000
When ducts are used, they must be of the same cross-sectional area
as the free area of the openings to which they connect. The
minimum dimension of rectangular ducts must be at least 3 in. (See
Fig. 3.)
Step 3—Supply-Air Plenum Installation
INSTALLATION ON A CONCRETE SLAB
1. Construct hole in floor per dimensions in Fig. 4 and Table 3.
2. Install plenum and furnace as shown in Fig. 5.
A
HOLE IN
FLOOR
Fig. 4—Floor Opening for Concrete Slab
Table 3—Opening Dimensions
FURNACE CASING
A
WIDTH
14-3/16 13-1/8
17-1/2 16-7/16
21 19-7/8
24-1/2 23-7/16
* These dimensions apply when a model CB or CD Evaporator Coil casing is
to be installed.
INSTALLATION ON A COMBUSTIBLE FLOOR
1. Cut and frame hole in floor per dimensions in Installation
Instructions packaged with downflow subbase.
ROUND PIPE (IN.
DIA)
16.5 5
22.0 6
27.5 6
33.0 7
ROUND PIPE (IN.
DIA)
33.0 7
44.0 8
55.0 9
66.0 10
B
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B
Heat-Only Heat/Cool*
19-5/8 19-7/16
19-5/8 19-7/16
19-5/8 19-7/16
19-5/8 19-7/16
Fig. 5—Furnace on a Concrete Slab (Non-Garage
2. When completed, downflow subbase, plenum, and furnace (or
coil casing when used) should be installed as shown in Fig. 6.
(OR COIL CASING
Fig. 6—Furnace, Plenum, and Subbase Installed on
a Combustible Floor
5
FURNACE
PLENUM
Installation)
FURNACE
WHEN USED)
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
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