Additionally, vertical terminations must be a
minimum of 3 feet (0.9 m) above the roof
line, and when less than 10 feet (3.05 m)
from a parapet wall must be a minimum of
2 feet (0.61 m) higher than the parapet wall.
Vent caps should have a minimum clearance
of 4 feet (1.2 m) horizontally from, and in
no case above or below [unless a 4 feet
(1.2 m) horizontal distance is maintained],
electric meters, gas meters, regulators and
relief equipment.
Maintain a distance of at least 3 feet (0.9
m) above any forced air inlet within 10 feet
(3.05 m) and a distance of at least 4 feet
(1.2 m) below, 4 feet (1.2 m) horizontally
from, or 1 foot (30 cm) above any door,
window or gravity air inlet.
Do not terminate the vent in a window well,
stairwell, alcove, courtyard or other recessed
area. The vent can not terminate below
grade. The bottom of the vent terminal shall
be located at least 12 inches (30 cm) above
grade and clear of snow, ice, leaves or
other debris.
The distance of the vent terminal from
adjacent public walkways, adjacent
buildings, windows, and building openings
must be consistent with the National Fuel
Gas Code Z223.1 or in Canada, the latest
edition of CGA Standard B149 Installation
Code for Gas Burning Appliances and
Equipment.
Masonry Chimneys
A masonry chimney must be properly sized
and lined for the installation of a high
efficiency gas fired appliance. Venting of a
high efficiency appliance into a cold,
oversized and unlined masonry chimney can
result in operational and safety problems. A
standard masonry chimney must not be used
to vent the products of combustion from this
high efficiency gas fired appliance.
A masonry chimney must be carefully
inspected to determine its suitability for
the venting of flue products.
An unlined chimney must be relined with
an approved chimney liner system when a
new appliance is being attached to it. Metallic
liner systems (Type "B" double-wall or flexible
or rigid metallic liners) are recommended for
non-condensing, negative draft systems.
Sealed, metallic, corrosion resistant liner
systems (single-wall, double-wall, flexible or
rigid metallic liners) rated for use with a high
efficiency, Category IV appliances must be
used with positive pressure systems.
Corrosion resistant chimney liner systems
are typically made from a high grade of
corrosion resistant stainless steel such as AL29-
4C. The corrosion resistant liner must be
properly sized and fully sealed throughout the
entire length contained within the masonry
chimney. Both the top and bottom of the
masonry chimney must be capped and sealed
to provide a dead air space around the liner.
L o c h i n v a r
D E S I G N E R
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G U I D E
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W A T E R
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7
IMPORTANT!
The vent cap should
have a minimum
clearance of 4 feet
horizontally from
electric meters, gas
meters, regulators, air
inlets and air relief
equipment. Additionally,
the vent cap should
never be located above
or below these items,
unless a 4 foot
horizontal distance
is maintained.
NOTE:
An unlined masonry
chimney must not be
used to vent flue
products from this
high efficiency
appliance.
