22 BULLETIN 98, U. S. DEPARTMENT OF AGRICULTURE. 
frigerating capacity of the system. With this system it is possible 
to prevent the air in the cold-storage compartment from becoming 
contaminated by contact with the melted ice and insanitary bunkers, 
as is the case when ice is used. In addition, a drier, purer air is 
maintained in the storage room. 
In milk plants, creameries, and dairies, where the cooling is done 
in a comparatively short time, it is necessary to have a large stor- 
age tank for brine, which may be cooled in the afternoon or over- 
night and held for quick action when needed. As the temperature 
of the brine in the storage tank will gradually rise as the work of 
cooling the mill?: goes on, the volume required will depend on the 
amount of milk to be handled and the range of temperature through 
which it is to be cooled. 
For example, if there are 1,000 pounds of milk to be cooled from 
an initial temperature of 90° F. to a final temperature of 35° F., 
the heat that must be removed is 1,000X0.95 (90-35) =52,250 
B. T. U. Then, if the initial temperature of the brine is 25° F. ; the 
allowable rise in temperature will be 10°, and if the specific heat of 
the brine is 0.83, neglecting radiation, the amount necessary will be 
52 250 
n gQvm "^ 2 pounds, or 87.5 cubic feet. It is assumed above 
U.oo /\ IU 
that the brine is pumped from a brine tank through some form of 
tubular cooler. 
CONSTRUCTION AND LOCATION OF COLD-STORAGE ROOMS. 
In the construction of cold-storage rooms consideration should be 
given to the relations that the lateral dimensions bear to the cubical 
space of the room. This is an important factor in the construction 
of refrigerators and is one to which but little attention is given. 
It is important that the shape of the room should be given first con- 
sideration, and unless there are some local conditions that compel a 
different arrangement it should be built, as nearly as possible, in the 
form of a cube. This will present the smallest exterior surface for a 
given cubical space for any practical form of construction. For 
very small rooms, however, of less than 1,000 cubic feet capacity, 
it is impracticable to .build them in the form of a cube, as the height 
should be 10 or 12 feet. This height affords a better circulation of 
air, and consequently a more uniform temperature, a purer, drier air, 
and more satisfactory refrigeration. 
Where mechanical refrigeration is employed this height is neces- 
sary in order to provide space for the coil bunkers unless wall coils 
are used, in which case the height may be less. The circulation of air, 
however, is not so good with wall coils as with a bunker loft. If very 
cold temperatures are not required, as in the case of ordinary ice 
