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15627-5-0807
Venting
1. Flue pipe must be as large as the flue collar on the draft
diverter.
2. Maintain an upward slope of at least 1/4 inch (6mm) per
foot of horizontal run.
3. Run flue pipe as directly as possible with a minimum of
elbows.
4. Flue pipe should extend through the wall of a chimney
to be flush with inner wall.
5. Flue pipe must be adequately supported by metal
straps.
6. Single wall vent pipe may be attached directly to the draft
hood of the fireplace heater when a clearance of 2 1/2 inches
(64mm) is maintained between the single wall vent pipe and
the combustible wall of the room in which the fireplace heater
is located. Use double wall vent pipe for clearances less than
2 1/2 inches (64mm) to combustibles.
7. For flue pipe running through walls and roof, use B-1 [1
inch (25mm) clearance to combustibles] vent pipe.
8. Chimneys should extend at least 2 feet (.6m) above the
roof and above any object or nearby building within 10 feet
(3m).
9. Open tees should not be used in the flue pipe.
10. Appliance must not be connected to a chimney flue that is
servicing a separate solid-fuel burning appliance.
For proper venting, do not attach a 90° elbow directly to draft
diverter. If possible, attach 2 feet (.6m) of straight vent pipe before
an elbow is used. Use of 45° elbows is recommended.
Uninsulated single-wall metal pipe shall not be used outdoors
in cold climates for venting gas utilization equipment.
Ventilation and Combustion Air
Fireplace heaters shall be installed in a location in which the
facilities for ventilation permit satisfactory combustion of gas
and proper venting under normal conditions. In buildings of
conventional frame, brick or stone construction without tight storm
windows and doors, infiltration is normally adequate to provide
for combustion and draft hood dilution.
Where appliances are installed in a confined space within a
building, the building being of unusually tight construction, air for
combustion and ventilation must be obtained directly from outdoors
or from such spaces that freely communicate with the outdoors.
Under these conditions, the confined space shall be provided with
two permanent openings, one near the top of the enclosure and one
near the bottom; each opening shall have a free area of not less
than one square inch (6.5cm
2
) per 1,000 BTU's (.3KW) of total
input. The draft hood must be in the same atmospheric pressure
zone as the combustion air inlet to the appliance and shall be so
located so that the relief opening is accessible for checking vent
operation.
Liner and Insulated Liner
When you install a vented fireplace heater into a masonry chimney
you must follow these steps.
1. The chimney must be lined and sized properly. Most masonry
chimneys are over sized and absorb too much heat to be
considered a proper vent. If you have any doubts line the
chimney with the right size liner. If it's unlined you must line
it.
2. Use an insulated liner when the chimney is on the outside,
three sides exposed to the weather, and there is no clay liner
in the chimney. The insulation will help keep the flue gases
warmer.
Insulated Vent Enclosure (Figure 15)
Vented fireplace heaters installed with the vent going directly to
the outside and above the eaves can cause poor venting. The cold
pipe will have a delay in proper venting and cause the fireplace
heater to shut "off" by the vent safety switch. To prevent delayed
venting as well as condensation of flue products an insulated
enclosure is recommended.
Use type B 4" (102mm) diameter vent pipe and maintain at least
a one inch (25mm) clearance to combustibles.
Use metal thimble to protect vent pipe as it passes through
combustibles
.
Figure 15
VENTING
