The following facts about ice and ice houses comes from Five Acres and Independence by M. G. Kains. Five Acres and Independence is also available to purchase in print.
Facts About Ice
Ice forms from water at a temperature of 0 centigrade or 32º F.
A cubic foot of solid ice weighs 58 pounds; a cubic foot of water, 62 1/2 pounds; therefore ice is 9/10 the weight of water.
Ice occupies 1/10 more space than the volume of water that forms it. One ton of solid ice occupies 36 cubic feet, but as stored in icehouses it requires about 45 cubic feet of space.
Ten pounds of ice has about the same cooling effect as 100 pounds of cold well water. Every pound of ice in melting abstracts 142 units of heat or enough to cool 10 pounds of water 14.2 degrees F.
Cooling by ice is due to melting. The faster ice melts the greater becomes its value as a cooling medium. This is why salt is mixed with ice; its great power to absorb water hastens the rate of melting. Salt can be used profitably at the rate of 1 part to 3 of crushed ice.
In sustaining power, ice in a sheet 2″ thick will usually bear a man; one 5″ thick, a team of horses and a load weighing 2 tons.
The best quality of ice is obtained from pure, clean, quiet water. Snow and slush are injurious to quality and keeping power.
Ice has a specific heat of 0.5, or exactly half that of water; i.e., the temperature of ice changes twice as fast as that of water.
The quantity of ice required on the farm will depend on location, number of cows milked, methods of handling the product, kind and site of ice-house, size of family and whether or not a household refrigerator is used.
To supply average family needs about 5 tons of ice should be stored; i.e., about 50 cakes 22″ square and 12″ thick, allowing for considerable waste. For dairy purposes 3,000 pounds per cow will be needed where whole milk is cooled, and 1,000 pounds where only cream is cooled.
Cost of storing varies with localities and distance ice must be hauled—about $1.50 a ton when near-by.
Table 8
Materials for Building an Ice House
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