Harman Stove Company 44 Magnum, Owner'S Manual

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11
Chimney Connectors and
Chimneys
Draft
Draft is widely misunderstood. It is impor-
tant 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 flow
there will not be a draft.
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 baro-
metric pressures, super insulated homes and ex-
haust fans can reduce draft. Winds can play havoc
with draft; therefore, if your chimney is too large or
too small it may cause reduced draft due to the
excessive cooling or not enough room to vent
exhaust gases quickly.
Introducing outside air directly to the stove
may help remedy a low draft problem. Some signs
of inadequate draft are smoking, odor, difficulty in
maintaining the fire, and low heat output. Over-
draft can be caused by a very tall chimney even if it
is the recommended size, and can cause overfiring
of your stove. Signs of an overdraft include rapid
fuel consumption, inability to slow the fire, 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 44 Magnum will produce enough
hot gases to keep the chimney warm so that ad-
equate draft is maintained throughout the burn
cycle.
Chimney Connectors
In general, following these guidelines will ensure
compliance with all national and provincial codes. Prior
to beginning your installation, check with your local build-
ing code official to check on additional local regulations
which may influence the design and placement of your
venting system.
The Harman 44 Magnum may be installed with
(150 mm) 24 gauge chimney connector pipe. The size
of the connector 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 space, closet or other concealed space, or
through a floor 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.
Assemble the connector beginning at the flue
collar, with the crimped ends pointing towards the stove
(to keep debris and creosote flakes inside the system).
Each joint, including the one to the stove’s flue collar
and the one to the chimney itself should be secured
with at least three sheet metal screws. A 1-1/4" (30
mm) overlap is required at each joint, including the flue
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 connec-
tor must have a minimum upward slope of 1/4"(6 mm)
per foot (20 mm per meter).
Wall Pass-throughs
Occasionally it is necessary to pass the chimney
connector through a combustible wall to reach the chim-
ney. Depending on your local building codes, and the
pertinent provincial or national codes, there are several
choices for accomplishing this safely. Before beginning
your installation, contact local officials, and also the chim-
ney connector and chimney manufacturer for specific
requirements.
Canada. Three methods are approved by the
Canadian Standards Association. The diagram shows
one method requiring an 18"(450 mm) air space be-
tween 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 InThe NFPA (National Fire Pro-
tection Association) 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 chim-
ney connector, and fill it with brick masonry which is at
least 3.5"(90 mm) thick. A fireclay liner, minimum 3/8"