111206-16 VISTA
and
CLASSIC-C
11
CREOSOTE FORMATION AND NEED FOR REMOVAL
CHIMNEY FIRES
The result of excessive creosote buildup is a chimney fi re.
Chimney fi res are dangerous. Chimney inside temperatures
can exceed
2000
° F. This causes much higher than normal
temperatures in the chimney and on its exterior surfaces. Thus
ignition of nearby or touching combustible material is more
likely during a chimney fi re. Proper clearances are critical
during such a fi re.
Chimney fi res are easy to detect; they usually involve one or
more of the following:
-Flames and sparks shooting out of the top of the chimney
-A roaring sound
-Vibration of the chimney
IN CASE OF A CHIMNEY FIRE
1
. Prepare to evacuate to ensure everyone's safety. Have a
well understood plan of action for evacuation. Have
a place outside where everyone is to meet.
2
. Close air inlet on stove.
3
. Call local fi re department. Have a fi re extinguisher handy.
Contact your local municipal or provincial fi re authority for
further information on how to handle a chimney fi re. It is
most important that you have a clearly understood plan
on how to handle a chimney fi re.
4
. After the chimney fi re is out, the chimney must be cleaned
and checked for stress and cracks before starting another
fi re. Also check combustibles around the chimney and the
roof.
AVOIDING A CHIMNEY FIRE
There are two ways to avoid chimney fi res:
1
. Do not let creosote build up to a point where a big chimney
fi re is possible.
2
. Do not have fi res in the heater that may ignite chimney
fi res. These are hot fi res, such as when burning household
trash, cardboard, Christmas tree limbs, or even ordinary
fuel wood; (e.g.. with a full load on a hot bed of coals and
with the air inlet excessively open.)
W
hen wood is burned slowly, it produces tar and other or-
ganic vapours, which combine with expelled moisture to form
creosote. The creosote vapours condense in the relatively
cool chimney fl ue of a slow burning fi re. As a result, creosote
residue accumulates on the fl ue lining. When ignited, this
creosote makes an extremely hot fi re. The chimney connec-
tor and chimney should be inspected at least once every two
months during the heating season to determine if a creosote
buildup has occurred. If creosote has accumulated, it should
be removed to reduce the risk of a chimney fi re.
1
. Highest smoke densities occur when a large amount of
wood is added to a bed of hot coals and the air inlet is
closed. The heated wood generates smoke, but without
ample air, the smoke cannot burn. Smoke-free, clean burn-
ing requires small fuel loads, two or three logs at a time
or
1/4
to
1/2
of fuel load and leaving the air inlet relatively
wide open, especially during the fi rst
10
to
30
minutes
after each loading, when most of the smoke generating
reactions are occurring. After
30
minutes or so, the air
inlet can be turned down substantially without excessive
smoke generation. Wood coals create very little creosote-
producing smoke.
2
. The cooler the surface over which the wood smoke is
passing, the more creosote will be condensed. Wet or
green wood contributes signifi cantly to creosote formation
as the excess moisture that is boiled off cools the fi re, mak-
ing it diffi cult for the tars and gases to ignite, thus creating
dense smoke and poor combustion. This moisture-laden
smoke cools the chimney, compounding the problem by
offering the smoke the ideal place to condense.
In summary, a certain amount of creosote is inevitable
and must be lived with. Regular inspection and cleaning
is the solution. The use of dry, seasoned wood and ample
combustion air will help to minimize the buildup.
