Where the ice house and dairy are required without the cold storage room, the plan shown in [Fig. 71] is a good one. If a location on a sidehill is not conveniently at hand, the milk room floor may be excavated sufficiently to secure proper fall for drain. The floor of the ice house should be laid with hydraulic cement, and slope toward the end nearest the milk room. A cheaper floor is made from spent moulders’ sand or coal ashes, mixed with enough lime to give a hard finish when dry. This makes a hard, durable floor. The water in the tank must be kept above the supply pipe from the ice house, to prevent any ingress of warm air. A trap placed in this pipe is a still better method. At L, [Fig. 71], is a double door, through which ice can be taken out for the tank if required.
The size of these rooms can be taken at convenience. The ice house should not be less than twelve feet square and twelve feet high. Any smaller quantity than this wastes the ice much more rapidly. A house sixteen feet square and twelve feet high is a safe size for a dairy which is served by forty cows or less. The lumber for walls is better if matched, and the studding lined with paper. They are, however, often built from rough lumber, with no air spaces. The packed section should be ten inches in such cases.
A Freezing House.—In some instances it is required to have a freezing temperature in the cold storage room. Poultry, dressed and frozen, and shipped in tight cases, has given good returns. This low temperature is secured by means of galvanized sheet iron tanks, Figs. [75], [77], [78], which are packed with broken ice and salt. From the surface of these tanks the cold is radiated directly into the room; hence, the larger the surface of the tanks for a given capacity of ice and salt, the better, because of the large radiating surface.
FIG. 74. COLD STORAGE HOUSE COMBINED WITH DAIRY.
The best form for the tanks is that of a hollow parallelogram. The lower edge should set about eighteen inches above the floor, to allow a circulation of air through the center of the tank. The tank should be a little wider at the bottom than at the top. This prevents the ice and salt from lodging. A tank six feet high, sixteen feet long, and three feet wide, placed at one side of the storage room shown in [Fig. 68], and regularly supplied with ice and salt, will reduce the temperature of the room nearly to O° F. As long as the supply of ice and salt is maintained, this low temperature can be held. The tanks are furnished with a trap to carry off the water, placed at the lowest end, and hand holds are arranged through which the salt which accumulates at the bottom may be removed. A drip pan is set beneath the tanks to catch all drippings of condensation; these pans are of wood, lined with metal, and provided with a pipe to carry off the water.
FIG. 75. SECTION OF REFRIGERATING TANK.
Frost and ice accumulate on the surface of these cooling tanks, and their usefulness is thereby impaired. Duplicate tanks should be arranged, so that they may be used in turn, and the ice removed. The ice coat prevents the radiation of the cold into the room, and its force is spent in adding to the ice upon the sides of the tank, a useless waste.
In some instances the cold storage houses are divided into two or more rooms, so that various temperatures can be maintained to meet the requirements of a varied stock.