Pacific Energy SERIES-B Installation And Operating Instructions Manual - page 5
5
Chimney Smoke and Creosote
Formation
When wood is burned slowly, it produces tar and other organic
vapours, which combine with expelled moisture to form creosote.
The creosote vapours condense in the relatively cool chimney flue
of a slow burning fire. As a result, creosote residue accumulates
on the flue lining. When ignited, this creosote makes an extremely
hot fire. 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 fire.
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 first 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 significantly to creosote formation as the excess
moisture that is boiled off cools the fire, 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 ample combustion air will help
to minimize annoying smoke emissions and creosote buildup.
Chimney Fires
The result of excessive creosote buildup is a chimney fire. Chimney
fires 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 surfaces. Thus ignition of nearby
or touching combustible material is more likely during a chimney
fire. Proper clearances are critical during such a fire.
Chimney fires 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 fire department. Have a fire extinguisher handy.
Contact your local municipal or provincial fire authority for
further information on how to handle a chimney fire. It is most
important that you have a clearly understood plan on how to
handle a chimney fire.
4. After the chimney fire is out, the chimney must be cleaned and
checked for stress and cracks before starting another fire. Also
check combustibles around the chimney and the roof.
- The services of a competent or certified installer, (certified by the
Wood Energy Technical Training program (WETT) - in Canada,
Hearth Education Foundation (HEARTH) - in U.S.A.,) are strongly
recommended.
Avoiding a Chimney Fire
There are two ways to avoid chimney fires:
1. Do not let creosote build up to a point where a chimney fire is
possible.
2. Do not have fires in the heater that may ignite chimney fires.
These are very hot fires, 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.)
NOTE: WHEN CLEANING THE CHIMNEY, ALWAYS COVER THE
BAFFLE AIR TUBE THAT PROVIDES AIR TO THE BAFFLE
AFTER YOU REMOVE THE BAFFLE.
SUMMIT-B 280416-24