Cork insulation; a complete illustrated textbook on cork insulation ...

356 CORK INSULATION
interlinings of a good refrigerator, the doors and top, should cut it
off from the warm outside air. It's not fair to expect 100 pounds of
ice to cool the whole outside world! So a poorly insulated refrig-
erator, however handsome to look upon, is largely an ice-melting plant
that wastes ice and does not maintain sufficiently low temperatures.
The ideal is to have a hard-wood case about ^-inch thick (oak
is best) with the equivalent of at least two inches of corkboard between
this and the inside lining of porcelain. The "reason why" for
this is that such an interlining not only keeps heat out, but it will
not absorb moisture, and is rigid so that it will not sag leaving air
spaces.
FIG. 168.—WISE WOMEN KNOW GOOD RKKRIGERATORS.
Merely wood, paper and air will not keep the heat out of the
refrigerator, such walls leave the ice badly handicapped in its war
with outside heat! Ask to see a cross-section of the refrigerator walls.
If the makers are proud of their box, they will be glad to "show"
you.
On these protecting walls and well-insulated and tightly closing
doors depends largely the coolness of the food compartments. They
should average 20 to 26 degrees colder than outside the refrigerator
when the room thermometer reads 70 to 75° F. As the weather
grows colder, this difference grows less. Under the ice, the coldest
place, the thermometer should read not more than 45° F., and on
the top shelf of a side-icer or on the bottom of a top-icer, the temperature
should not be much more than 50° F. when the room is
70 to 75^ F.
Circulation Means "Air Move On."— "Side-Icer or Top-Icer"? That
is a question, too.