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

CORKBOARD INSULATED REFRIGERATOR 385
These obserxations are based on a refri^^erator cabinet
of fair quality, as respects <strong>insulation</strong>; but as the permanent
insulating qualities of mechanically cooled household refrigerators
are improved, so the difiticulties of food compartment
temperature control are reduced. The well insulated unit,
such as a cabinet containing three inches of pure corkboard set
tightly against the interior lining at all points, is not sensitive
to room temperature fluctuations to any appreciable degree,
and consequently may easily perform its two major functions
with that degree of accurac}- required by a discriminating
owner. At the same time, such a mechanical unit can be
operated at a cost that will be low enough to justifv the
extra investment.
In testing mechanical units, the same test conditions
should be observed as outlined for ice refrigerators, with but
a few changes. The kiloAvatt-hours power consumption is
measured instead of ice melted. A gi\en quantity by weight
of water at say 70° F. temperature is filled into standard cube
trays that have been cooled to the same temperature, and the
trays are placed in the refrigerator once e\'ery day for the
cubes to be frozen, the frozen cubes from the day before being
simultaneously removed. If it is desired to put a normal
"food load" on either the ice cooled or the mechanically cooled
refrigerators, same should amount to 8 B.t.u. per hour, per
cubic foot of cabinet contents, same being introduced electric-
ally by an immersion heater in a container of oil placed at a
given point in the food compartment.
On account of the lower temperatures in general desired
by owmers and maintained in mechanical units, especial
attention must be paid to the subject of condensed moisture
within the wall construction of the mechanically cooled cabinet
at the end of the 30-day test period.