Martin Fireplaces 400BWBIA - Manual (Page 35)

61D0008 35
FIREPLACE OPERATION
WOOD VS. FOSSIL FUELS
Compared to fossil fuels, a full cord of dry hickory weighs
about two tons and is approximately equal in heating value
to a ton of hard coal. On a per pound basis, heavy hardwoods
have about half the heating value of coal. The table below
shows the relative densities and heat values of a variety of
dry woods. Varieties at the top of the list (Dogwood) burn
longer and those near the bottom (White Pine) ignite and
burn quicker. A combination of both light and heavy wood
is desired.
SPECIES VALUE DENSITY HEAT
Dogwood .70-.79 100-107
Hickory .70-.74 100
Oak .60-.73 86-99
Black Locust .69-.70 95-98
Beech .64-.66 89-91
Hard Maple .58-.65 83-88
Birch .55-.64 79-86
Apple .58-.62 83-84
Ash .57-.61 81-82
Southern Pine .51-.60 73-81
Elm .50-.59 71-80
Cherry .50-.52 70
Douglas Fir .45-.51 64-69
Spruce .41-.44 59
Redwood .33-.40 47-54
White Pine .35-.37 50
A FEW WORDS OF CAUTION
Do not burn plastics, poison ivy twigs and stems and chemi-
cally treated woods such as discarded poles and railroad ties
in your fireplace. These create air pollution and can cause
extreme irritation for some people.
Use hemlock, spruce, juniper and other resinous woods with
caution. They contain moisture pockets which, upon heating,
“pop” with considerable vigor.
Always use a fire screen. Always “bank” a fire (or at least push
all unburned fuel to the rear of the grate) before leaving a fire
unattended. Do not use this fireplace as an incinerator.
The termination of the chimney above the roof is exposed to
wind, cold, and pressure changes. These and other environ-
mental conditions may make it hard to get a sufficient chimney
draft at times. At other times the draft may be sufficiently
disrupted and cause smoke to spill from the fireplace opening.
If problems with chimney draft occur, help start chimney draft
before you build a fire by holding a piece of burning paper
near the flue opening at the top of the firebox to preheat the
chimney. If smoke spills from the fireplace opening after the
fire is burning, open a window on the up wind side of the house
that is far enough away form the fireplace that the wind will
not blow across the fireplace opening. Push burning wood as
near the back of the fireplace as possible. If your fireplace has
glass doors, close them.
IMPORTANT: Do not leave children or physically or
mentally handicapped, or senile persons alone with a
burning fireplace.