Venting And Chimney Requirements - Williams 4505621 Installation & Operating Instruction Manual

Venting And Chimney Requirements
Proper venting of this furnace is required to prevent the
release of hazardous gases into the dwelling. The furnace
must always be vented into a vertical vent. This vent may be
a listed type "B" gas vent or masonry chimney. The following
statements are intended as a guide for venting the furnace.
If other venting requirements are required by local codes,
the local codes must be adhered to.
If the furnace is to be vented into a masonry chimney, be
sure the chimney is lined, clean and in good repair. Be sure
the vent system is installed by a qualified installer and -
1. Do not connect this furnace to a chimney flue sewing
a seperate solid fuel (coal or wood) buming appliance.
Soot and creosote deposits from the solid fuel heating
appliance can block the vent serving this furnace.
2. If this furnace is to be connected to a chimney that
has previously been used for a solid fuel appliance,
clean the chimney thoroughly of all deposits that
might drop down and block the furnace vent.
3. The total length of the horizontal run of vent connector
pipe must not exceed 75 percent of the height of the
gas vent or chimney above the point where the vent
connector is attached. All venting material must be
supported by hangers spaced a maximum of four
(4) feet apart and attached to the floor joist or by
other methods approved by local codes.
4. The horizontal vent connector must be not less than
4 inches in diameter and not more than 6 inches in
diameter.
5. The horizontal vent connector must slope upward
from the furnace to the chimney at least 1/4 inch per
foot of connector length.
6. Avoid using a vent or chimney for more than one
furnace if it is practical, but if it is necessary to use
one vent for two furnaces, be sure the vent or chimney
has an interior liner at least 6 inches in diameter.
7. If two furnaces are connected to a chimney or vent
with a common vent connector, join the unit connectors
as shown in Figure 3. Do not join the vent connectors
with a tee. Be sure to size the vent connectors as
shown in Figure 3.
8. Use a thimble when attaching the vent connector to
a masonry chimney, and place the thimble at least 6
inches above the bottom of the chimney. Seal the
vent connector and thimble joint to prevent gases
from escaping.
9. Keep the vent connector at least 6 inches from all
combustible material and if the vent connector must
pass through a partition constructed of combustible
materials, use a thimble in the partition that has been
listed for this use by a nationally recognized testing
agency. An improperly installed vent connector can
overheat adjacent materials and cause a dangerous
fire.
10. Be sure that there are no unsealed openings in the
vent or chimney that will decrease the chimney draft
and the chimney is at least 2 feet higher than all parts
of the building within 10 feet. This is required to
reduce the possibility of wind interfering with the draft
(see Figure 4).
11. If the furnace is to be vented into a masonry chimney,
be sure the chimney is lined, clean and in good repair.
12. Never terminate a vent pipe inside an attic, under
the building, in a closet or with a horizontal run of
vent pipe. The vent pipe must extend above the roof
of the building as shown in Figure 4.
FIGURE 3
-- FLOORFURNACE
DRAFTHOOD
VENT PIPE2
[_ 45°ELL
VENT PIPEI
45" Y BRANCH. DO NOT CONNECT
VENT PIPE TOGETHER AT 90 °
ANGLES
"'Y" CONNECTION NO MORE THAN
12"' FROM VERTICAL FLeE
DO NOT EXTEND VENT PIPE PAST
INSIDE OF FLUE LINER
Size Vent Pipe 1 Size Vent Pipe 2 Size Vent Pipe 3
4"" 4"' 6'
5- 5" 7""
6- 6"" 8'
VENT PIPE
FLUE
WRONG RIGHT
13. Do not use an uninsulated vent pipe. An uninsulated
vent pipe can cause a fire hazard by overheating
adjacent combustible matedals. An uninsulatedvent
pipe can also cause condensation of the vent gases
within the pipe and retard the draft.
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