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1. Adequate air supply must be provided for combustion
and venting of appliance. Local codes or NFPA 54 specify
minimum requirements for combustion ventilation and
dilution air.
NOTE: Failure to provide adequate air may result in
extreme hazards to life.
2. Ameri-Vent Gas Vent is suitable for installation inside
or outside. However,the sizing tables in NFPA 54 are for
vents not exposed to the outdoors below the roof line.
Outside vents could reduce venting action; therefore,
such installations are not recommended. In the event
outside venting is necessary, vents should be sized as
close to maximum capacity as possible. Whenever pos-
sible outside vents should be enclosed inside a chase
which maintains the minimum one (1) inch clearance to
combustibles. Appliances served by an outside vent
must have an adequate air supply to balance inside
and outside air pressure to reduce the possibility of
reverse venting action.
3. The vent should be sized for the sea level name
plate input rating of the appliance in accordance with
the procedures set forth in NFPA 54 (The National Fuel
Gas Code), or the American Metal Products Gas Vent
Capacity Tables (EP-GVC).
4. When installing, make sure arrow on the Ameri-Vent
part is pointed up or away from the appliance.
5. When installed as a Type B Gas Vent, a minimum of
one (1) inch air space clearance to combustible mate-
rial is required. For Type B 2x4 and BW Vents see
Section 2, page 9 for clearance to combustibles. All
locking joints are to be securely snap-locked together.
See the rear page of these instructions for detailed
information about locking and unlocking vent sections.
The first vent section must be screwed to the appliance
outlet collar.
6. Ameri-Flex Model FC Gas Vent Connector should
be installed in accordance with our installation instruc-
tions. Unlisted single wall connector pipe shall be
securely supported and joints fastened with sheet
metal screws, rivets or other approved means. At the
point of connection of the single wall connector pipe to
the double wall gas vent, three sheet metal screws or
rivets may be used as an approved means.
NOTE: Do not use sheet metal screws at the lock
joints of Ameri-Vent Model E, R, and O Gas Vents
7. Wherever possible, install vertical vents directly
above appliances before beginning any lateral runs.
Lateral venting should be kept to a minimum to avoid
vent resistance. Horizontal runs to vents should either
be in accordance with the appropriate tables in NFPA
54, or should not exceed 75% of the vertical height of
the vent. Laterals should be supported. Excessive
General Installation Guidelines
number of fittings, such as elbows and tees, should be
avoided.
8. Maintain a pitch or rise from the appliance to the vent
cap on horizontal runs. The pitch shall not be less than 1/4
inch to the foot.
9. Vents must terminate vertically above the roof line.
Refer to the Termination of Vent Structure section on page
10 for details.
10. Strap or support vents securely in position to maintain
a minimum of one (1) inch air space clearance to
combustibles.
11. Firestops must be used where vents pass through
floors or ceilings.
12. More than one gas appliance may be vented into a
common vent. Close attention should be paid to vent
sizing to assure adequate venting action.
13. Portions of gas vents which may extend through
accessible spaces are to be enclosed to:
a) Maintain the one (1) inch minimum air space
clearance.
b) Avoid personal contact with the vent.
c) Avoid damage to the vent.
IMPORTANT:The enclosure must provide a minimum
of one (1) inch air space to all combustible material
and building insulation. Refer to section 2, page 9 for
Type B 2x4 and BW clearances.
14. In many types of buildings, such as multi-family
residential, high-rise and others, vents which pass through
floors or ceilings must be located in fire rated shafts or
chases with no openings, except for inspection access.
Consult local building code for proper wall construction,
access, clearance, support, initial penetration of breeching
and method of termination, or refer to the National Fuel
Gas Code (NFPA 54).
15. Never vent gas appliances into an unlined masonry
chimney. Install either Type B Gas Vent or a listed metal
relining system inside chimney to reduce condensation
and reduce the chances of improper venting which could
occur in unlined chimneys.
NOTE: While handling sheet metal parts, it is
advisable to wear gloves to avoid personal injury
from sharp edges or projections.
16. If a power vent fan is used, make sure it is located at
the terminus so as to maintain negative pressure within
the vent.
17. The gas venting system should be inspected prior to
the heating season by a qualified technician. This
inspection should include removal of the cap to confirm an
unrestricted vent.
