The Brookings register. [volume] (Brookings, Brookings County, S.D.) 1903-1971, 1915-04-01
THE FUEL VALUE OF WOOD

The fuel value of two mounds Of
wood is roughly equivalent to that OF
n pound of coal. This is given as
the result of certain calculations now
being made in the forest service labor
atory, which show also about how
many cords of certain kinds of wood
are required to obtain an amount OF
neat equal to that in a ton of coal.
Certin kinds of wood, such as hick.
ory' oak, beech, birch, hard maple,
ash' elm, locust, longleaf pine, and
cherry, have fairly high heat values,
and only one cord Of seasoned wood
OF these species is required to equal
one ton of good coal.
1t takes a cord and a half of short
Teal pine, hemlock, red gum, Douglas
hr, sycamore, and soft Maple to equal
a ton of coal, and two cords of cedar.
redwood, poplar, catalpa, Norway pine,
cypress, Eastwood, spruce, and white
pine.
Equal weights Of dry, n~on-resinous
woods, however, are said to have prac-
tcally the same heat value regardless
OF species, and as a consequence it
can be stated as a general proposition
that the heavier the wood the more
heat to the cord. Weight for weight.
however, there is very little difference
between various species; the average
heat for all that have been calculated
is 1900 calories, or heat units, per
kilogram. A kilogram of resin will
develop 9,4O0 heat units, or about
twice the average for wood. AS a con
sequence, %resinous woods have a
greater heat value per pound than
non-resinous woods, and this increas-
ed value varies, of course, with the
resin content.
The available heat value of a cord
of wood depends on many different
factors. 1t has a relation not only to
the amount of resin it contains but to
the amount Of moisture present. Fur
thermore, cords vary as to the amount
of solid wood they contain, even
when they are of the standard
dimension and occupy 12S cubic feet
Of space. A certain proportion of this
space is made up of air spaces be-
tween the sticks, and this air space
may be considerable in a cord made of
twisted, crooked and knotty sticks.
Out of the 128 cubic feet, a fair aver
age of solid wood is about so cubic
feet.
1t is pointed out, however, that heat
value is not the only test of usefulness
in fuel wood and since 95 per cent Of
all wood used for fuel is consumed for
domestic purposes, largely in farm
houses, such factors as rapidity of
burning and ease of lighting are i'm
portant. Each section of the country
has its favored woods and these are
Sdlu W US, III Stlltldl, Tie llSHI OutS
to use. Hickory, of the non-resinous
woods, has the highest fuel value per
unit volume of wood, and has other ad-
vantages. 1t burns evenly, and, as
housewives say, holds the heat. The
oaks come next, followed by beech,
birch, and maple. Pine has a relative
ly low heat value per unit volume, but
has other advantages. 1t ignites read
lily and gives out a quick hot fame,
but one that soon dies down. Thi>
makes it a favorite with rural house
keepers as a summer wood, because ii
is particularly adapted for hot days in
the kitchen.
The fuel qualities Of chestnut adapt
it particularly to work in brass found
ries, where it gives just the required
amount of heat and it is therefore in
favor. Coastwise vessels in Florida
pay twice as much for Florida button
wood as for any other, because it
burns with an even heat and with a
minimum amount of smoke and ash.
The principal disadvantage of the
resinous pines is their oily black
smoke.