Ductwork Acoustical Treatment; Supply Air Connections; Return Air Connections; Gas Piping - Carrier 58CVA Installation, Start-Up, Operating And Service And Maintenance Instructions

For a furnace not equipped with a cooling coil, the outlet duct shall
be provided with a removable access panel. This opening shall be
accessible when the furnace is installed and shall be of such a size
that the heat exchanger can be viewed for possible openings using
light assistance or a probe can be inserted for sampling the air
stream.

DUCTWORK ACOUSTICAL TREATMENT

Installation tip: Metal duct systems that do not have a 90 degree
elbow and 10 ft of main duct to the first branch take-off may
require internal acoustical lining. As an alternative, fibrous duct-
work may be used if constructed and installed in accordance with
the latest edition of SMACNA construction standard on fibrous
glass ducts. Both acoustical lining and fibrous ductwork shall
comply with NFPA 90B as tested by UL Standard 181 for Class 1
Rigid air ducts.

SUPPLY AIR CONNECTIONS

Upflow and Horizontal Furnaces
Connect supply-air duct to flange on furnace supply-air outlet.
Bend flange upward to 90° with wide duct pliers. The supply-air
duct attachment must ONLY be connected to furnace supply-
outlet-air duct flanges or air conditioning coil casing (when used).
DO NOT cut main furnace casing to attach supply side air duct,
humidifier, or other accessories. All accessories MUST be con-
nected external to furnace main casing. Supply air opening duct
flanges must be modified per Fig. 14.
Installation tip:For horizontal applications, the top most flange
may be bent past 90 degrees to allow the evaporator coil to hang
on the flange temporarily while the remaining attachment and
sealing of the coil are performed.
Downflow Furnaces
Connect supply-air duct to supply-air opening on furnace. The
supply-air duct attachment must ONLY be connected to furnace
supply/outlet or air conditioning coil casing (when used). When
installed on combustible material, supply-air duct attachment must
ONLY be connected to the accessory subbase, KGASB0201ALL,
or factory approved air conditioning coil casing. DO NOT cut
main furnace casing to attach supply side air duct, humidifier, or
other accessories. All accessories MUST be connected external to
furnace casing. Supply air opening duct flanges must be modified
per Fig. 14.

RETURN AIR CONNECTIONS

Never connect return-air ducts to the back of the furnace. A
failure to follow this warning can cause a fire, personal injury,
or death.
Downflow Furnaces
The return-air duct must be connected to return-air opening
(bottom inlet) as shown in Fig. 1. DO NOT cut into casing sides
(left or right). Side opening is permitted for only upflow and
certain horizontal furnaces. Bypass humidifier connections should
be made at ductwork or coil casing sides exterior to furnace. (See
Fig. 19.)
Upflow and Horizontal Furnaces
The return-air duct must be connected to bottom, sides (left or
right), or a combination of bottom and side(s) of main furnace
casing as shown in Fig. 1. Bypass humidifier may be attached into
unused side return air portion of the furnace casing. See Fig. 18
and 20.
Not all horizontal furnace models are approved for side return air
connections. See Fig. 20.
Step 6—Gas Piping
Gas piping must be installed in accordance with national and local
codes. Refer to current edition of NFGC in the U.S. and the
NSCNGPIC in Canada.
Installations must be made in accordance with all authorities
having jurisdiction. If possible, the gas supply line should be a
separate line running directly from meter to furnace.
Refer to Table 4 for recommended gas pipe sizing. Risers must be
used to connect to furnace and to meter. Support all gas piping
with appropriate straps, hangers, etc. Use a minimum of 1 hanger
every 6 ft. Joint compound (pipe dope) should be applied sparingly
and only to male threads of joints. Pipe dope must be resistant to
the action of propane gas.
If a flexible connector is required or allowed by the authority
having jurisdiction, black iron pipe shall be installed at the
gas valve and extend a minimum of 2 in. outside the furnace.
Use a new flexible connector for each installation. Never
re-use an old flexible connector.
Connect gas pipe to furnace using a backup wrench to avoid
damaging gas controls.
Never purge a gas line into a combustion chamber. Never use
matches, candles, flame, or other sources of ignition for
purpose of checking leakage. Use a commercially available
soap-and-water solution to check for leakage. A failure to
follow this warning could result in fire, explosion, personal
injury, or death.
Use proper length of pipe to avoid stress on gas control
manifold. Failure to follow this warning could result in a gas
leak resulting in fire, explosion, personal injury, or death.
Table 4–Maximum Capacity of Pipe*
NOMINAL
IRON INTERNAL
PIPE DIAMETER
SIZE (IN.)
(IN.)
1/2 0.622
3/4 0.824
1 1.049
* Cubic tf if gas per hr for gas pressure of 0.5 psig (14–in wc) or less, and a
pressure drop of 0.5–in wc (based on a 0.60 specific gravity gas).
Ref: Table 9.2 NFGC.
Install a sediment trap in riser leading to furnace as shown in Fig
21. Connect a capped nipple into lower end of tee. Capped nipple
should extend below level of gas controls. Place a ground joint
union between gas control manifold and manual gas shutoff valve.
A 1/8-in. NPT plugged tapping, accessible for test gage connec-
tion, MUST be installed immediately upstream of gas supply
connection to furnace and downstream of manual shutoff valve.
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LENGTH OF PIPE (FT)
10 20 30 40 50
175 120 97 82 73
360 250 200 170 151
680 465 375 320 285