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 Burning Firewood
The
Fine Art of burning
Wood in a Wood Burner.
It must be
understood that no two heating days (or nights)
are exactly the same. And so, all the
many variables
must be controlled to the best of our ability.
If we could control density, size,
shape, and moisture
of every piece of Firewood; ambient air
temperature;
plus rooftop wind
speed and direction,
then life would
be a dream.
Dream on . . .
Your method of
placing Wood in a Wood Burner
can
determine your success or failure, and your delight or disgust.
Putting Firewood in a Wood Burner is properly called, "Building a Fire".
Using a plan to position pieces of Firewood will greatly affect the heat output.
Boy Scouts are taught to stack firewood like a
Tepee,
which allows
Oxygen to enter the bottom and exit the top like a Chimney.
In fact . . . it
actually creates a Chimney.
The hot air which the fire creates, rushes out the top
like a hot-air Balloon.
And the Tepee shape protects feeble embers
from the wind.
In the photo above, you will see a similar "Chimney Effect" inside a
Wood
Burner.
The two pieces of Firewood are laid close together at their tops,
so
the
flames from the Kindling have maximum contact with the dry wood.
The
flames are seen shooting out the top of the "Chimney".
If the two pieces of Firewood were separated, they
would not produce the same Chimney Effect. The more hot air that rushes
out the top; the more cool air is drawn in the bottom to replace it.
This concentrated air movement has the same effect as a mild Blower
whipping up the flames.
You should consider this Chimney Effect when you load a Wood Burner.
If you pack it full and tight, it will have trouble breathing, and may
"Smother".
This condition creates more smoke and Creosote
than heat.
For instance, if you were burning boards and laid them flat on top of
the embers, they
would tend to insulate and smother the fire. But standing them on edge
would allow
more air passages. If a third piece of Firewood was laid on top of the
existing two in the photo above, the Chimney Effect would be
diminished,
and so would the flames, and the heat.
This retarded condition is OK if you plan to stoke a fire for an
extended period, where
heat output is not as important as preserving the fire.
But for quick, comforting heat; remember the Chimney Effect.
This
graphic shows a smothered fire on the left and one with good air
movement which will create "Chimney effects" between the pieces of
Firewood.
The blue diamond represents an object placed there to position the
firewood and maintain a "Chimney". It can be a small chunk of wood
which will have served its purpose by the time it burns up. It is best
placed toward the rear, so it does not block draft. It can also be a piece of metal, which can be reused.
A Log is commonly split into 4 equal pieces. The quarter-round split
Firewood on the right benefits from being placed with the curvature up
since it exposes 27% more wood in contact with the glowing Embers.
Narrower splits will benefit even more from this positioning; a 1/8
split would double the exposure to 54%.
Fine split Kindling exposes maximum surface area to embers and releases
its BTU's very quickly, compared to burning the whole Log or Limb. If
you want quick heat, place the Firewood for maximum exposure and draft,
being careful not to overheat your Wood Burner.
Oxygen is
essential for Combustion !
 There is a given amount of
Oxygen consumed
to produce a
given amount of BTU's.
The amount of
Oxygen entering the Draft Inlet
determines the
size of the fire.
The flame
nearest the Draft Inlet,
will get the
most Oxygen.
There will be
NO Oxygen available at the back of
the
Wood Burner, until the fire
near the Draft Inlet is satisfied.
A fire started
near the Draft Inlet
will progress
toward the back slowly.
A fire started
near the back
will progress toward the
Draft Inlet Oxygen much faster.
The bottom line is:
Ignite your Kindling near the back, and build the
Firewood
on the Kindling, and toward the Draft Inlet,
or be prepared for slower warmth.
A
weekly handful of common Table Salt thrown on a hot fire
is said to turn Creosote into harmless dry flakes.
If you want a spectacular fire; these Firewoods make lotsa Sparks:
Hemlock, Chestnut, Tamarack, Larch, Spruce, Cedar, Yellow Poplar.
(Be sure to have a tight-fitting fireplace Screen).
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