Lennox Hearth TRADITIONS T150C - Manual (Page 9)

INSTALLATION
PAGE 9
CHIMNEY HEIGHT REQUIREMENTS
The chimney must extend 3 feet (914 mm) above the
level of roof penetration and a minimum of 2 feet (610
mm) higher than any roof surface within 10 feet (305 cm)
(see below). Check with your local building officials for
any additional requirements for your area.
Due to prevailing winds, local terrain, adjacent tall trees,
a hill, or ravine near the home, or adjacent structures,
additional chimney height or a special chimney cap may
be required to ensure optimum performance.
To achieve a stable draft, the total flue height required
(from the appliance to termination) is 12 to 15 feet (366 to
457 cm) minimum.
DRAFT REQUIREMENTS
The appliance is merely one component of a larger sys-
tem. The other equally important component is the vent-
ing system. This is necessary for achieving the required
flow of combustion air to the fire chamber and for safely
removing unwanted combustion byproducts from the ap-
pliance. If the venting system's design does not promote
these ends, the system may not function properly. Poorly
functioning venting systems may create performance
problems as well as be a safety hazard (i.e. an oversized
chimney may result in less than optimum performance.
Installations into a large, masonry chimney may require a
liner to improve performance). A draft test should read
greater than .04' W.C. (inches water column) and less
than .08" W.C.
American National Standards Institute ANSI/NFPA 211-
92: A chimney or vent shall be so designed and con-
structed to develop a flow sufficient to completely remove
all flue and vent gases to the outside atmosphere. The
venting system shall satisfy the draft requirements of the
connected appliance in accordance with the manufac-
turer instructions.
Top of the flue must be
2’ (610 mm) higher than
any part of roof within
10’ (305 cm) horizontal
These rules are minimums. in some instances,
chimney height may need to be increased to
achieve sufficient draft.
Top of the flue must be 3’ (915
mm) higher than highest point
of roof penetration