
6
Design Considerations
When selecting a chimney type and the location for
the chimney in the house, keep this in mind: It is the
chimney that makes the stove work - not the stove that
makes the chimney work. is is because a chimney
actually creates a suction, called “dra” which pulls air
through the stove.
Several factors aect dra: chimney height, cross-
sectional area (size), and temperature of the chimney,
as well as the proximity of surrounding trees or
buildings.
A short exterior masonry chimney will give the
poorest performance because it will be dicult to
warm the ue and sustain the temperatures necessary
to maintain dra strength. In extremely cold climates,
it may be necessary to reline the chimney or extend the
height to help establish dra.
A tall, interior masonry chimney is easier to keep
warm and will perform the best under a variety of
weather and environmental conditions.
e following guidelines give the necessary chimney
requirements based on the national code (ANSI-NFPA
211 for the US. And CSA CAN-B365 for Canada).
However, many local codes dier from the national
code to take into account climate, altitude, or other
factors. Your local building inspector is the nal
approving authority.
Masonry Chimneys
Follow these guidelines when installing the stove into a
masonry stove:
• e masonry chimney must have a reclay liner or
equivalent, with a minimum thickness of 5/8” (14
mm) and must be installed with refractory mortar.
ere must be at least 1/2” (12.7 mm) air space
between the ue liner and chimney wall.
• e reclay ue liner must have a nominal size of
8” X 8” (20 cm x 20 cm), and should not be larger
than 8”X 12” (20 cm x 30 cm). A round reclay
liner must have a minimum inside diameter of 6”
(15 cm) and maximum inside diameter of 8” (20
cm). A larger chimney should be relined with an
appropriate code approved liner.
• Brick or modular block must be a minimum of 4”
(10 cm) nominal thickness. Stone construction
must be at least 12” (30 cm) thick.
• A newly-built chimney must conform to local
codes, or, in their absence, must comply with na-
tional regulations.
• An existing chimney must be inspected by a pro-
fessional, licensed chimney sweep, re ocial, or
code ocer to ensure that the chimney is in proper
working order. Any repairs must be completed
before installing the stove.
• No other appliance may be vented into the same
ue.
• An airtight clean-out door should be located at the
base of the chimney.
Chimney Height
• e chimney must be at least 15 feet high (4.57
m). e chimney must also be at least 3 feet (92
cm) higher than the highest point where it passes
through the roof and at least 2 feet (61 cm) higher
than the highest part of the roof or structure that is
within 10 feet (3.05 m) of the chimney, measured
horizontally. See Fig 2.
• Chimneys shorter than 15 feet may not provide ad-
equate dra. Inadequate dra can result in smoke
spillage when loading the stove, or when the door
is open. Poor dra can also cause back pung (ig-
nition of gas build-up inside the rebox) and slug-
gish performance. e minimum height does not,
in itself, guarantee proper chimney performance.
Optimum dra force should be in the .05 - .10 in.
w.c. range measured by a Magnehelic gauge. Dra
at .07 w.c. is ideal.
• Excessive chimney height can promote over-strong
dra resulting in high stove temperatures and short
burn times. Excessive dra can be corrected by in-
stalling a buttery damper. Your dealer is an expert
resource to consult regarding dra issues or other
performance-related questions.