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Save These Instructions 3-90-798 Dry Seasoned Wood Only!
Draft is widely misunderstood. It is important that
you, the stove operator, realize that draft is a variable
effect, not a given quantity. Stoves and chimneys
do not have draft, yet draft is the key to your stove’s
performance.
Draft is a force, produced by an operating stove
and the chimney to which it is attached. It is created by
hot gases rising up the chimney, creating a pressure
difference between the inside of your home and the
outside air. It continually moves fresh combustion air
into the stove, and hot exhaust gases out of the stove;
without this constant ow, the re will go out.
Other factors, such as barometric pressure,
winds, the airtightness of the home, the total inside
chimney volume, chimney height and the presence
of venting devices such as exhaust fans also play a
role in maintaining an adequate draft. Low barometric
pressures, super insulated homes and exhaust fans can
reduce draft; winds can play havoc with draft; and too
large or too small a chimney volume can cause reduced
draft due to the excessive cooling or not enough room
to vent exhaust gases. Introducing outside air directly
to the stove may help remedy a low draft problem.
Some signs of inadequate draft are smoking, odor,
difculty in maintaining the re, and low heat output.
Overdraft can be caused by a very tall chimney even if
it is the recommended size, and can cause overring
of your stove. Signs of an overdraft include rapid fuel
consumption, inability to slow the re, and parts of the
stove or chimney connector glowing red. It is important
that you follow the chimney guidelines in this manual,
including size, type, and height to avoid draft problems.
When installed and operated according to this
manual, the Oakleaf will produce enough hot gases
to keep the chimney warm so that adequate draft is
maintained throughout the burn cycle.
In general, following these guidelines will ensure
compliance with all national and provincial codes;
prior to beginning your installation, check with your
local building code official to check on additional
local regulations which may inuence the design and
placement of your venting system.
The Harman Oakleaf may be installed with a minimum
(.6 mm) 24 gauge chimney connector pipe. The size of
the connector should correspond to the size of the ue
collar opening. Do not use makeshift compromises. No
part of the chimney connector may pass through an
attic or roof space, closet or other concealed space,
or through a oor or ceiling. Whenever possible, avoid
passing the connector through a combustible wall; if you
must, use an approved wall pass-through, described
later in this section.
Depending on your local building codes, and the
pertinent provincial or national codes, there are several
choices for passing the chimney connector safely
through a wall. Before beginning your installation,
contact local ofcials, and also the chimney connector
and chimney manufacturer for specic requirements.
Canada. Three methods are approved by the
Canadian Standards Association. The diagram on the
next page shows one method requiring an 18"(450 mm)
air space between the connector and the wall. It allows
use of one or two covers as described in the diagram.
The two other methods are described in detail in the
current issue of CAN/CSA B365, the national standard.
United States In the U.S., the national code is NFPA
211. While many localities adopt this standard, be sure
to check with local authorities before beginning your
installation.
The NFPA (National Fire Protection Agency) permits
four methods for passing through a combustible wall. A
commonly used method to pass through a wall directly
to a masonry chimney is to clear a minimum 12"(300
mm) around the entire chimney connector, and ll it
with brick masonry which is at least 3.5"(90 mm) thick.
A reclay liner, minimum 3/8" (9 mm) wall thickness
must run through the brick wall to the chimney liner (but
not beyond the inner surface of the liner). It must be
cemented in place with refractory cement. This method
is illustrated on the next page. For details on the other
three options, refer to the most recent edition of the
NFPA 211 code.
Assemble the connector beginning at the ue collar,
with the crimped ends pointing towards the stove (to
keep debris or residue inside the system). Each joint,
including the one to the stove’s ue collar and the one
to the chimney itself should be secured with at least
three sheet metal screws. Screws may be a maximum
of 3 inches apart. A 1-1/4" (30 mm) overlap is required
at each joint, including the ue collar attachment. No
more than two 90 degree elbows should be used, and
the total length of connector should not exceed 10 feet
(3 m). All horizontal runs of connector must have a
minimum upward slope of 1/4"(6 mm) per foot (20 mm
per meter).
The chimney connector diameter should correspond
to the size of the flue collar opening. Do not use
makeshift compromises. No part of the chimney
connector may pass through an attic or roof cemented
in place with refractory cement.