The Washington times., 1920-08-15
HOW ELECTRIC ICE-BOX
CAUSES REFRIGERATION

Many people ask from time to time
what DEVILS magic causes electricity,
the force which Is used to heat a nat
iron or light a lamp. to "blow cold as
well as hot"--to produce cold as
easily as IL provided warmth and
light.
As q matter OF fact. the electrical
"iceless Ice box" does not produce
cold by means of electricity but only
utilizes the power OF an electric
motor to manipulate chemicals or
gases. which are the actual refriger-
ants.
Mechanical refrigeration is simply
the production OF GELD by vaporiza-
tion or boiling. Everyone knows. that
when heat Is applied to water. the
latter will boil away. Heat is alb
sorbed by the water; the water Vap-
orizes; the heat which causes this
boiling is actually used up" in the
process.
A similar thing happens In the
electric refrigerator. Instead Of
water, which vaporizes at 212 de-
grees Fahrenheit. a refrigerant is
used which "boils" or vaporizes at
something like II degrees, or about
IS degrees colder than the freezing
point OF water. The refrigerants
most commonly used are sulphur
dioxide. ethyl chloride and methyl
chloride.
One OF these chemicals is COM
pressed in the motor driven ap-
paratus and is condensed into liquid
form. 1t then passes into a copper
tube and begins to boil or vaporize.
Since II vaporizes at point con-
siderably below the freezing point OF
water 1t absorbs or "uses up" the
heat from the surrounding air, just
as water uses up the heat OF a fire.
and naturally this air becomes colder
and colder. The process OF absorb
ing the heat from the air inside the
Ice box continues as long as there is
any compressed gas in the machine
to vaporize.
Since the compressed gas Is secured
by the operation OF the compressor,
run by the electric motor. the temper
ature of the refrigerator can be con-
trolled by controlling the operation of
the motor. This control Is automatic,
thermostat and switch starting the
motor when the temperature in the
box rises to a certain point and shut
ting the motor off again as soon as
the temperature has sufficiently
fallen.
Thus when the ice box door Is fire.
quently opened. or left open a few
minutes, the automatic controller i'm
mediately starts the "cold maker"
and keeps 1t going until the box is
again the proper degree Of coolness.
Mechanical refrigeration provides
dry cold. partly because there is no
dampness due to the melting of ice
and partly because whatever damp
ness may exist within the BOX is
quickly CONCEALED into frost upon the
pipes which contain the refrigerant.
This phenomena is exactly the same
as frost upon a window When a
room is damp during cold weather,
the moisture Immediately congeals
upon the glass and the room becomes
relatively free from dampness.
Electrically operated. iceless refrig-
orators are said to be quite inexpen-
sive as compared with equal service
from ice. Tests on household types of
these machines show that a box re-
quiring refrigeration equal to the
melting of 100 pounds of ice each
twenty-four hours costs from to IL
cents a day for upkeep, this expense
maintaining the box at Al degrees
when the average room temperature
was SO degrees Fahrenheit.