Carrier 58DH - Venting

Place a ground joint union between the gas control
manifold and the manual gas shutoff valve. See Fig. 4.
A WARNING
Use the proper length of pipes to avoid stress on the
gas control manifold.
Protect all segments of the piping system against
physical and thermal damage. Support all piping with
appropriate straps, hangers, etc. Use a minimum of one
hanger every 6 feet. For pipe sizes larger than 1/2 in.,
follow recommendations of national codes.
A CAUTION
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 casing.
Piping should be pressure tested in accordance with
local and national plumbing and gas codes before furnace
has been attached. If pressure exceeds 0.5 psig( 14 in. wg),
gas supply pipe must be disconnected from furnace before
pressure test. If test pressure is equal to or less than 0.5
psig (14 in. wg), close manual shutoff valve located on gas
valve before test. Ground joint union should be loosened
before pressure testing.
After all connections have been made, purge the lines
and check for leakage. _
A WARNING
Never purge a line into a combustion chamber. Never
use matches, candles, flame, or other sources of
ignition for the purpose of checking leakage. Use a
soap-and-water solution to check for leakage.
VENTING
-+ Venting Category I — This furnace complies with
Venting Category I, as noted on the furnace rating plate.
This refers to the type of venting system as specified in the
ANSI 21.47 requirements, against which this appliance is
tested and design certified by the American Gas Associa¬
tion Laboratories. Specifically, Venting Category 1 is a
nonpositive venting system, meaning the static pressure
in the vent is less than atmospheric pressure, and the stack
gas temperature is at least 140 degrees F above the dew
point temperature. Do not attempt to confirm this data
by field measurement, as specific laboratory equipment
and test conditions are required.
Consult local codes. For additional information refer
to the National Fuel Gas Code (NFPA No. 54-1984 or
ANSI Z223.1-1984). Unless the local codes direct other¬
wise, unit may be vented to an NFPA- or ANSI-approved
chimney, or to a listed type-Bl gas vent. Connect the
vent collar to the chimney or gas vent to be used. Follow
these recommendations:
1. Select flue connection material that is satisfactory
for installation and that meets requirements of local
codes.
2. Flue connection pipe must be at least as large as
outlet collar on furnace. No reduction in this size is
permissible in pipe run.
NOTE: The clearance requirements which must be
maintained between the furnace vent pipe and com¬
bustible materials are as follows: 6 in. for single-wall
vent and one in. for type-Bl (double-wall) vent.
When B1 vent material is used, make the single wall-
to-Bl transition with a listed transition fitting
directly on the flue collar or flue extension pipe.
3. Run pipe as directly as possible with minimum
number of turns and minimum of 12 in. straight pipe
before the first bend (upflow and downflow).
4. Maintain minimum of 1/4in. per linear ft upward
slope on all horizontal runs.
5. Rigidly support flue pipe with hangers and straps to
ensure that there will be no movement after
installation.
6. Insert smallest flue connection pipe at highest level
consistent with available headroom or clearance to
combustible materials, when 2 or more vent con¬
nectors enter a common gas vent or chimney flue.
7. Extend flue connection pipe through chimney wall
flush with inner face of chimney liner and above
extreme bottom to avoid restriction.
A WARNING
Never connect into a chimney serving a fireplace
unless the Fireplace opening is sealed off.
8. No portion of venting system shall extend into, or
pass through, any circulating air duct or plenum.
9. Chimney or gas vent shall extend at least 5 ft above
highest connected draft hood and should extend high
enough above roof or neighboring obstruction, so
that wind from any direction will not create positive
pressure in vicinity of chimney or gas vent outlet.
Chimney or gas vent should extend 3 ft higher than
point of emergence through roof, and at least 2 ft
higher than any object within a radius of 10 feet. See
Fig. 5.
10. A type-Bl gas vent shall terminate above roof surface
with a listed cap or roof assembly.
Common Venting with Other Appliances —
This furnace may be connected to a common chimney or
listed type-Bl gas vent with other listed gas-fired appli¬
ances. The vent system of this induced-draft furnace
operates at negative pressure during normal operation. If
for any reason the pressure in the vent system becomes
positive (may happen if chimney is inadvertently
blocked), the furnace shuts down and locks off. This is
accomplished by means of draft safeguard switch located
on tube attached to relief box just above draft inducer
blower. The design of this furnace, equipped with draft
safeguard switch, has been tested by the American Gas
Association Laboratories.
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