1. Highest smoke densities and emissions 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 burning 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 pass-
ing, 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, making
it difficult 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 am-
ple combustion air will help to minimize annoying smoke
emissions and creosote buildup.
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(1100˚C). This causes much higher than
normal temperatures in the chimney and on its exterior sur-
faces 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 inlets on stove.
3. Call local fi re department. Have a fi re extinguisher handy.
Contact your local 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 cracking before starting an-
other fi re. Also check combustibles around chimney and
the roof.
- The services of a competent or certifi ed installer, (certifi ed
by the Wood Energy Technical Training program (WETT) - in
Canada, Hearth Education Foundation (HEARTH) - in U.S.A.,)
are strongly recommended.
Over Firing
Over fi ring can be caused by operating the unit with the door
open, damage to door gaskets allowing excess air to enter
the fi rebox, the use of kiln dried lumber, mill ends or paper
waste and prolonged or continual use on a high burn setting.
Heat Output Calculation
Seasoned wood has approximately 7500 BTU’s per pound.
The calculation is as follows:
Experience will give you the right settings for proper com-
bustion and efficient burning. Remember the correct air inlet
setting is affected by variables such as type of wood, outside
temperature, chimney size and weather conditions. With
practice, you will become profi cient in operating your heater
and will obtain the performance for which it was designed.
Proper Draft
1) Draft is the force which moves air from the appliance up
through the chimney. The amount of draft in your chimney
depends on the length of the chimney, local geography,
nearby obstructions and other factors.
2) Too much draft may cause excessive temperatures in the
appliance. An uncontrollable burn or a glowing red stove
part or chimney indicates excessive draft.
3) Inadequate draft may cause backpuffing into the room and
plugging of the chimney. Smoke leaking into the room
through appliance and chimney connector joints indicates
inadequate draft.
Ash Removal
Whenever ashes get 3”(76mm) to 4”(102mm) deep in your
fi rebox, and when fi re has burned down and cooled, remove
excess ashes. Leave an ash bed approximately 1”(25mm)
deep on the fi rebox bottom to help maintain a hot charcoal bed.
Disposal of Ashes
Ashes should be placed in a metal container with a tight fi t-
ting lid. The closed container of ashes should be placed on
a non-combustible fl oor or on the ground, well away from all
combustible materials, pending fi nal disposal. If the ashes
are disposed of by burial in soil or otherwise locally dispersed,
they should be retained in the closed container until all cinders
have thoroughly cooled. Other waste should not be placed
in this container!
Chimney Smoke and Creosote
Formation
When 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 connector
and chimney should be inspected periodically (at least once
every two months) during the heating season to determine if
a creosote buildup has occurred. If creosote has accumulated
(3 mm. or more), it should be removed to reduce the risk of
a chimney fi re.
Amount of wood in lbs. X 7500BTU’s
Burn rate in Hrs.
X .8(80% Avg. Efficiency)
20
051
6
-2
0
VISTA
INSERT-D
11
