Upflow Installations - Goodman VC8 Installation Instructions Manual

When sizing a trunk line, be sure to include all appliances
which will operate simultaneously.
The gas piping supplying the furnace must be properly sized
based on the gas flow required, specific gravity of the gas, and
length of the run. The gas line installation must comply with
local codes, or in their absence, with the latest edition of the
National Fuel Gas Code, NFPA 54/ANSI Z223.1.
Natural Gas Capacity of Pipe
In Cubic Feet of Gas Per Hour (CFH)
Length of
Pipe in Feet 1/2"
10 132
20 92
30 73
40 63
50 56
60 50
70 46
80 43
90 40
100 38
(Pressure 0.5 psig or less and pressure drop of 0.3" W.C.; Based on
0.60 Specific Gravity Gas)
CFH = BTUH Furnace Input
Heating Value of Gas (BTU/Cubic Foot)
To connect the furnace to the building's gas piping, the installer
must supply a ground joint union, drip leg, manual shutoff valve,
and line and fittings to connect to gas valve. In some cases,
the installer may also need to supply a transition piece from 1/
2" pipe to a larger pipe size.
The following stipulations apply when connecting gas piping.
• Gas piping must be supported external to the furnace
cabinet so that the weight of the gas line does not
distort the burner rack, manifold or gas valve.
• Use black iron or steel pipe and fittings for the building
piping.
• Use pipe joint compound on male threads only. Pipe
joint compound must be resistant to the action of the
fuel used.
• Use ground joint unions.
• Install a drip leg to trap dirt and moisture before it can
enter the gas valve. The drip leg must be a minimum
of three inches long.
• Install a 1/8" NPT pipe plug fitting, accessible for test
gage connection, immediately upstream of the gas
supply connection to the furnace.
• Use two pipe wrenches when making connection to
the gas valve to keep it from turning. The orientation
of the gas valve on the manifold must be maintained
as shipped from the factory.
• Install a manual shutoff valve between the gas meter
and unit within six feet of the unit. If a union is installed,
the union must be downstream of the manual shutoff
valve, between the shutoff valve and the furnace.
• Tighten all joints securely.
Nominal Black Pipe Size
3/4" 1" 1 1/4"
278 520 1050
190 350 730
152 285 590
130 245 500
115 215 440
105 195 400
96 180 370
90 170 350
84 160 320
79 150 305
• Connect the furnace to the building piping by one of
the following methods:
–
Rigid metallic pipe and fittings.
–
Semi-rigid metallic tubing and metallic fittings.
Aluminum alloy tubing must not be used in exterior
locations.
–
Use listed gas appliance connectors in accordance
with their instructions. Connectors must be fully in
the same room as the furnace.
1 1/2"
–
Protect connectors and semi-rigid tubing against
1600
1100
physical and thermal damage when installed.
980
Ensure aluminum-alloy tubing and connectors are
760
coated to protect against external corrosion when
670
in contact with masonry, plaster, or insulation, or
610
560 subjected to repeated wetting by liquids such as
530
water (except rain water), detergents, or sewage.
490
460
U I
PFLOW NSTALLATIONS
When the gas piping enters through the right side of the fur-
nace, the installer must supply the following fittings (starting
from the gas valve):
• Close nipple.
• 90 degree elbows.
• Straight pipe to reach the exterior of the furnace .
A ground joint union, drip leg, and manual shutoff valve must
also be supplied by the installer. In some cases, the installer
may also need to supply a transition piece from 1/2" to another
pipe size.
When the gas piping enters through the left side of the furnace,
the installer must supply the following fittings (starting from the
gas valve):
• 90 degree elbow.
• Straight pipe to reach the exterior of the furnace.
• A ground joint union, drip leg, and manual shutoff valve
must also be supplied by the installer. In some cases,
the installer may also need to supply a transition piece
from 1/2 inch to another pipe size.
20
Gas line
entrance
Right side
gas entrance
(alternate)
General Furnace Layout