19
BULLETIN RC454
A GUIDE TO BURNING COAL IN YOUR FURNACE
Furnaces that are capable of burning coal usually will burn
both Bituminous and Anthracite coal. Anthracite is perhaps
the best coal fuel because of its long even burn time, high
heat output, and cleanliness which make it a good choice
for the home. However, keep in mind it is a much more dif-
fi
cult fuel to use, requires more care and patience, is not
so widely available, and is usually much more expensive
than Bituminous.
SIZE OF COAL
Most sizes of Bituminous Coal will work in a coal furnace;
for best results we recommend large “nut” coal to small
“egg” coal (1-3/4” diameter to 4” diameter). When burn-
ing Anthracite, use “egg” or “broken” with sizes between
2-5/16” thru 4-3/8”. Note that it is important to the long
life of your stove to buy coal which has been sized and
cleaned. Cleaning insures removal of rocks and other min-
erals. Never use coal smaller than 1” or larger than 5” in
diameter. Small sized coal will smother the
fi
re. Too large
a size of coal will not burn well.
STOVE OPERATION
All coal
fi
res should be started with wood which will al-
low the
fi
re to get hot enough to ignite the coal. The best
ignition
fi
res utilize dry pine or other resinous soft woods
as kindling, with hard wood (oak, hickory, ash) added to
increase the heat prior to addition of the coal.
Before starting the
fi
re, open the stove pipe damper (if
epuipped), turn the thermostat to high, open the ash pit
door and feed door, place newspaper and
fi
nely split kin-
dling on the grate, light the paper, add larger hard wood
after the kindling is burning brightly. Caution: Never use
gasoline, lantern fuel, kerosene, charcoal lighter
fl
uid, or
other
fl
ammable liquids to start or freshen up a
fi
re in any
heater. Place the larger pieces of wood on the
fi
re so that
they are slightly separated and form a level for the addi-
tion of coal. It will take 10 to 20 minutes before this wood
is thoroughly ignited. Adding coal too soon will cut the air
supply and smother the
fi
re.
BURNING BITUMINOUS
Once your kindling and wood
fi
re has produced a bed of
well established coals, start adding coal in layers allowing
each to ignite before adding more. Bituminous has a high
volatile content and, as a result, should be
fi
red with the
“conical method” - with the highest portion of your
fi
re bed
in the center of the
fi
rebox. The
fi
rst
fl
ames will be long
and generally orange or yellow and produce quite a bit of
smoke. As the gases burn off the
fl
ames become shorter,
change color and produce less smoke.
Once the
fi
re is WELL ESTABLISHED add coal to the cen-
ter of the
fi
rebox forming the cone. Burning in this fashion
allows heat to drive off the volatile gases, and turbulence
created increases the burn ef
fi
ciency. There will have to
be some experimenting with the individual setup as no two
chimney’s or installations are going to be the same. Just
remember to allow enough air to enter the
fi
rebox and keep
the stove pipe damper open so that volatiles are properly
burned. Before refueling, take the time to break up the
cone a little with a poker, especially if it has caked over or
formed a crust. But, be careful not to mix the coal as this
increases the chances of forming clinkers. When shaking
the grate(s) be gentle. Just a few short movements - a
couple of “cranks” - is better than a lot of agitation. The
objective is to remove a small amount of the ashes without
disturbing the
fi
re. Stop when you see a glow in the ashes
or the
fi
rst red coals fall into the ash pan. Excessive shak-
ing wastes fuel and can expose the grate(s) to very high
temperatures which can cause warpage or burnout.
For overnight operation (long duration burn time) shake
the
fi
re and add coal, retaining the center cone. Once the
volatiles are burned off, close the feed door and adjust the
stove pipe damper, if epuipped. Then adjust the thermo-
stat to the desired heat level.
More MAINTENANCE will be needed with bituminous coal
than with anthracite coal as more soot will collect on heat-
ing surfaces and in pipes, requiring more frequent clean-
ing.
ANTHRACITE
Add a thin layer of coal (preferably smaller chunks) to the
wood
fi
re, being careful not to disturb it too much or cut off
the draft. Then, add a second heavier layer after the coal
is ignited and burning well. If necessary, add a third layer
to bring the coal up to the top of the front liner (not above!).
Be sure to close the ash door.
Before adding further fuel, be sure to leave a red spot of
glowing coals in the center of the
fi
rebox to insure that the
fi
re has not been smothered and to help ignite the gases
given off by the new charge. A deep charge will give a
more even heat and a longer
fi
re, but it may take one to
two hours before the whole bed is fully ignited.
