Venting And Chimney Requirements - Williams 4505622A Owner's Manual

INSTALLING YOUR FURNACE
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 lined 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 serving
a separate solid fuel (coal or wood) burning 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.
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 lined 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
8
FLOOR FURNACES
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.
13. Do not use an uninsulated vent pipe. An uninsulated
vent pipe can cause a fire hazard by overheating
adjacent combustible materials. An uninsulated vent
pipe can also cause condensation of the vent gases
within the pipe and retard the draft.
FIGURE 3 - UNIT CONNECTOR
FIGURE 4 - CHIMNEY HEIGHT