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Heating- Questions Answered.
BY FRANCIS A. HERENDEEN, GENEVA, N. Y.
How shall I heat my house ?
Everybody sooner or later asks this question.
The answer: Use a Hot-air furnace, Steam heat or a Hot-water
system. Many people combine the last two.
Which is the cheapest ?
First cost only considered,—Hot-air,—unless you use stoves.
Then why is the use of other systems constantly increasing?
Easily told, because, leaving out the question of first cost, they
are admittedly the most healthful and give a far
pleasanter and
evener heat with an abundance of pure fresh air, and besides are
vastly more economical in fuel.
In selecting a Steam or Hot-water apparatus, what is the most
importantfeature to consider ?
The Boiler, as it is the very heart and life of the entire system.
Are n’t all boilers about alike ?
For instance, examine the difference between “packed joints”
and “screwed joints.” The former never can be relied upon and
sooner or later are bound to give out and leak. Only lathe
turned screwed joints are safe, iron to iron; the longer used the
tighter they become. Remember this above all others, that the
weakest pointe about all boilers or radiators are their joints.
Therefore look to them critically.
What is a “packed joint?”
A packed joint is a connection made between two water open-
ings by means of a gasket or washer of paper, asbestos, rubber or
some other “spongy” material, placed around the opening be-
tween the two parallel faces of the iron and the entire joint made
tight by pressure, generally by bolting the two faces together.
Then why is a “packed joint” unreliable ?
Because the constant
strain it is subjected to by
expansion and contraction
soon deadens the elasticity
of the packing; the con-
stant heat dries it out, and
sooner or later it becomes
worthless, leakage
and incurring the trouble
and expense of
repacking.
Frequently they give out
in the middle of winter.
Remember also, that all
boilers of this type contain
from ten to twenty-five of these joints.
Then why are n’t boilers made without joints?
Because it is impossible to produce a boiler made in one piece
that would be practicable and burn the fuel economically, and
therefore it must be made in sections and connected together by
joints of some-kind.
What kind of
joints are best?
Lathe-turned screwed joints throughout; they will never leak.
How else do boilers differ ?
Well, in some, the water surfaces are horizontal
—arranged over
the fire; and in others, they are vertical.
Are horizontal surfaces better ?
Decidedly not. All horizontal surfaces are soon covered with
a
layer of fire ashes and soot and so prevent the heat being ab-
sorbed easily by the water, causing immense waste of fuel. The
accumulation of a quarter of an inch of soot requires 50 per cent,
more fuel than would be necessary if the surfaces were clean. j
But can’t they be cleaned ?
No, there are scarcely any. two
built the same way. Some are
made of wrought iron, and some
of cast iron; some are
tubular,
and some are sectional; some
are made “with packed joints”
and some with “screwed joints;”
some have plain grates, from
which it is difficult to remove
clinkers, others improved rock-
ing grates, and so on.
How can I tell which is the
best ?
By getting thoroughly iinform-
ed on each, under consideration.
They can be, yes, but in the average house where the boiler is
left to servants they are not. “Cleaning the boiler” is a dirty,
disagreeable job, filling the cellar with dust and soot, and the
practical result is the boiler is left to “do the best it can” by
itself.
But what about “vertical surfaces?”
They are necessarily perpetually clean. Being vertical, there is
no place where dust can lodge and collect, and therefore they
greedily absorb heat from the fire, and the smoke passes off cool.
But supposing the “vertical surface” are in the form of flues—-
verticle flues—what then ?
Ah, then these flues will choke up. All flues will choke up,
whether horizontal or vertical, and need constant cleaning. What
w
re mean by vertical surfaces that will be constantly cleaning are
convex vertical surfaces, such as the outside of tubes filled with
water.
Are wrought iron boilers preferable ?
Not for heating purposes; for where a boiler lies idle half the
year, as in a damp cellar through the summer months, it rusts out
rapidly. Cast iron as is well known, is not nearly so susceptible
to corrosion as wrought iron, and is therefore practically inde-
structible.
Of what material should a boiler be constructed ?
The best of cast iron throughout and every boiler should be
tested to a pressure ten times greater than it ever will be subject-
ed to at any time when it is in operation. With ordinary proper
care it should last a lifetime. Every inch of its iron in
any way
exposed to the fire should be constantly backed by solid water so
that it cannot burn out or rust out.
In a Hot-water system what is most essential ?
A rapid flow of water through the pipes and radiators.
Why so?
Because the faster the water travels the hotter will be its aver-
age temperature, and the more heat will it impart to the house.
What causes the water to circulate ?
Heat.
What retards its circulation ?
Friction
What creates friction ?
Sharp turns of the pipe, bad valves, poorly constructed radia-
tors, but most of all a horizontal movement of the water through
the boiler.
Why does a “horizontal movement” of the water through a
boiler create friction ?
Because when water is heated, it at once begins to expand and
rise —straight up—and if it has to move in a zig-zag way through
the boiler before being liberated into the flow pipes, the contact
of the water with the horizontal surfaces of each section
through
which it passes creates great friction, and, consequently, its veloc-
ity is greatly retarded.
How then should a Hot-water boiler be constructed so as to
produce rapid circulation ?
It should be constructed so that every particle of water, from
the moment it commences to absorb heat until it is discharged
into the flow-pipes, must move vertically through the boiler.
Thereby the minimum of friction and maximum of velocity of
the water are obtained.
What makes “Econemy of fuel ? ’
Three things: First, perfect combustion; second, rapid trans-
formation of fire-heat into water-heat; and third, the least waste
of heat from the boiler into the cellar.
What promotes “perfect combustion?”
A fire-box so constructed that the fire will burn evenly, as well
at the edge as at the center, and a draft sufficient to give an ample
supply of oxygen for the complete combustion of all the gases
generated.
What
promotes “rapid transformation of fire-heat into water-
heat.
Three things: First, the fire must lie in the midsts of and be
surrounded by water surfaces.
Second, the flames and hot gases must impinge, or strike,
against these surfaces at right angles; and
Third, The water must be cut up into small portions so as to
rapidly absorb heat. For instance you can boil a quart of water
on a stove much faster if you divide it into two portions of a pint
each. ,
What prevents waste of heat from the boiler into the cellar.
Setting the boiler in brick-work, or, if it is a “portable style,”
then encasing it in easily removable asbestos and iron jackets.
Are n’t all portable Hot-water boilers so encased?
Very few, scarcely any.
251
THE SOUTHERN ARCHITECT.

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