Location Recommendations; Gas Connection - Greenheck PVF Installation, Operation And Maintenance Manual

Location Recommendations

1. Do not install units in locations where flue products
can be drawn into adjacent building openings such
as windows, fresh air intakes, etc. Distance from
vent terminal to adjacent public walkways,
adjacent buildings, operable windows, and
building openings shall conform with the local
codes. In the absence of local codes, installation
shall conform with the National Fuel Gas Code,
ANSI Z223.1, or the CAN/CGA B-149 Installation
Codes.
2. Building materials that will be affected by flue
gases should be protected.
3. Avoid locating in an area where deep snow is likely
to accumulate. During the winter months, keep
snow clear on the access side of the unit to
prevent any blockage of combustion air inlet or
flue exhaust openings.
4. Maintain minimum horizontal clearance of 4 feet
from electric meters, gas meters, regulators, and
relief equipment. In Canada, the minimum
clearance is 6 feet.

Gas Connection

Gas Supply Pressure Requirements
Natural: 6 to 14 in. wg
LP: 11 to 14 in. wg
1. Single furnaces (furnace input 100 to 400 MBH)
have a single ⁄ inch connection. Double furnaces
3
4
(furnace input 500 to 800 MBH) have two
connections, and triple furnaces (furnace input
1050 to 1200 MBH have three
2. When connecting the gas supply, the length of the
run must be considered in determining the pipe
size to avoid excessive pressure drop. Refer to a
Gas Engineer's Handbook for gas pipe capacities.
3. A drip leg should be installed in the pipe run to the
unit.
4. Install an easily accessible ground joint union and a
manual shut off valve (these are required by some
local codes) for emergency shut off and easy
servicing of the controls.
5. A 1 ⁄ inch NPT plugged tap shall be installed
8
immediately ahead of the gas supply connection to
the furnace.
6. After gas piping is completed, carefully check all
piping connections for gas leaks. Use soap solution
or equivalent for testing. DO NOT use a flame or
other source of ignition to check for gas leaks.
2
3 ⁄ inch
4
3 ⁄ inch connections.
4
5. Local codes may supercede any of the above
provisions.
6. Be sure that the minimum clearances to
combustible materials are maintained.
Unit Clearances to Combustible Materials
Combustion blower discharge must be located
42 in. from any combustible materials.
Venting
1. Do not modify or obstruct the combustion air inlet
cover or the combustion blower weatherhood.
2. During the winter months, periodically clear snow
from access side of unit to prevent blockage of the
inlet and exhaust openings.
3. Do not add any vents other than those supplied by
the manufacturer.
7. When leak testing pressures above 14 in. wg (
close the field installed shutoff valve, disconnect
the furnace and its gas train from the gas supply
line, and plug the supply line before testing.
8. When leak testing at pressures equal to or less than
14 in. wg ( 1 ⁄ psi) close the field-installed shutoff
2
valve to isolate the unit from the gas supply line
before testing.
Ground Joint Union
Gas Cock
From
Gas
6 in. Trap
Figure 1: Recommended Piping to Controls
1 ⁄
2
To Controls
1/8 in. Plugged
psi),