CHAPTER VI.

THE USE OF ICE IN REFRIGERATION.

Cold Storage Ice Houses--Their Value for Handling Meats, Fruits and Vegetables--What They Will Do--Principles of Construction and Operation--How to Build Them--The Dairy and Cold Storage Houses--Convenience and Economy of Combining Them--Combined Ice House and Dairy--Very Cheap Ice Houses--How to Cut Ice in Small Quantities--Co-operation among Farmers to Secure Advantages of Ice Supplies.

THE USES OF REFRIGERATION are numerous in these days of invention and economy. The health, comfort and convenience of the civilized world are so intimately interwoven with results directly dependent upon the command, at will, of low temperature, that it is now of paramount importance to everyone.

Refrigeration in the commercial world is largely secured by mechanical means, and this method will receive notice in a later chapter. Cold storage, secured by ice, is in use all over this country, for domestic and trade purposes in preserving food products. The benefits of cold storage could be much more widely diffused, than at present, throughout all the farming communities, where ice forms naturally during the winter, adding materially to their profits and convenience, and an attempt is here made to show, in a practical way, how it can be secured.

THE CONSTRUCTION of a cold storage ice house, and the tools and methods employed for cutting and housing the ice, as well as the benefits to be secured, will be considered. Only such facts as have stood the test of practical experience, and which are within the limits usually attained by those who have good cold storage in use from year to year, will be presented. These results are only attainable by properly constructed storage houses, sufficient supply of ice, correct condition of articles when placed in cool room, length of time they are kept there and cleanliness. Cold storage houses, not built on correct principles, or improperly used, will prove of little account, and disappointment will follow their use.

Cold storage may be used to advantage in prolonging the market for many products. The entire crop, of fruit in particular, need not be shipped at once, but by proper picking and storing shipping can be extended over several months.

Fresh meat can be enjoyed at will, and the lengthening of the season during which many varieties of vegetables and fruits can be kept fresh for the home table will not only add to the health and enjoyment of the family, but it is in the line of economy as well. Good health is the best doctor, and the more generous living which cold storage brings within reach is a precursor of health. In sickness a supply of ice and cooled viands is often beyond price. The suffering its judicious use may alleviate, and the numerous instances in which recovery is impossible without it, commend a supply of so beneficent a commodity to all. Ice is a necessity to health and comfort, and, as it can be readily secured in nearly all communities within the frost belt, very few farmers should be without it.

HOW LONG COLD STORAGE WILL PRESERVE.--No rules as to the length of time during which various articles can be kept in cold storage to the best advantage, can be given, which will apply invariably to all cases. In stating what is often done in this way it is intended to show what it has been found profitable to do, and what will be likely to prove of practical value to those who are starting in to make use of cold storage for themselves. Poultry and fresh meats can be kept sweet for two or three weeks. Beef is improved in quality by keeping this length of time. Butter, eggs and lard may be stored for three to eight months. Apples, according to variety and condition, from five to ten months. Pears, pulled when they will just come away from the stem, and carefully handled, will keep two or three months. It is best to ship them in two or three weeks, not waiting for color to mature, as this will be perfected by the time they reach the consumer.

Concord grapes will keep two to four months in cold storage, and Catawba grapes will keep longer.

Strawberries, blackberries and cherries will keep two to four weeks.

Watermelons, three to six weeks.

Muskmelons, two to three weeks.

Peaches, four to six weeks.

Oranges, lemons, figs, bananas and raisins, two to three months.

Green corn, two to four weeks.

Squash, four to eight weeks.

Cabbage and turnips, eight to nine months.

Potatoes may be kept a long time; they have been kept, on a trial, several years, with no apparent loss of quality. Canned fruits will keep well, and ice cream can be conveniently stored.

THE TEMPERATURE at which these results have been secured varied from 34° to 38° F. Bananas, oranges, lemons, peaches, figs and raisins do better at 40°. Peaches, pears, berries, plums and all the more delicately flavored fruits keep in good form and appearance, but lose their delicate flavor if kept too long.

Fruits which are picked green, or before ripening, mature or ripen while stored. The tendency to decay in ripe fruits is arrested by refrigeration. Upon exposure to heat and air the usual process goes on more rapidly than in foods which have not been refrigerated. Food should enter into consumption with little delay when taken out of cold storage. The length of time during which it is desirable to keep goods in cold storage may be best determined practically with reference to the ends sought to be attained in any particular case.

THE PRINCIPLES OF COLD STORAGE.--Refrigeration depends upon the circulation of pure, dry cold air. It is based upon natural laws, which are well known and readily observed. Air exposed to heat is expanded in volume; it is thus made lighter and will rise, being forced upward by the surrounding cooler air. Air exposed to cold is condensed and made heavier; it will then gravitate to lower levels. The capacity of air for absorbing and retaining moisture varies with its temperature. Warm air will sustain a considerable amount of vapor, which will be condensed and precipitated if the air is cooled. As water is cooled and brought to the freezing point it expels a large part of the heat gathered at a higher temperature. As ice is melted to water this process is reversed, and heat and air are reabsorbed.

The operation of these natural laws is taken advantage of in refrigeration.

As usually constructed, cold storage ice houses are built with two stories; the first floor for storing goods, the second filled with ice. The floor between is arranged with openings, through which the air, chilled by contact with the ice, descends into the store room. A flue is provided to conduct the warm air to the upper part of the ice chamber, when it is dried and purified by contact with the ice as it descends on being chilled. Drains and traps are required to carry off the meltage water, and to secure the water condensed from the warm air. Dampers in the cold and warm air flues assist in controlling the circulation, and ventilators placed in the roof keep the loft free from dampness.

The walls, ground floor and ceiling are constructed as nearly non-conducting of heat and cold as practicable. No cracks or any channels are permissible by which air can enter. Drains which take out the water are securely trapped, to keep out the air. Vestibules with perfectly fitting doors are placed at all entrances. Windows are fitted with three or four sashes and air spaces between.

Dryness in the storage room is secured by a sheet metal floor under the ice, usually galvanized iron, which forms a large pan or vessel, in which all meltage water is collected. Water is very destructive to the ice, and the warm air is kept away from the top of the ice to prevent the moisture from being condensed there and settling on the ice. When the ice is low in the ice chamber, vapor may accumulate in the space above the ice. A ventilator in the top of the room is of service in conducting this away from the ice and keeping it dry. The water from the melted ice will absorb air and gases so it is spread out over as large a surface as practicable, and the air is conducted over it to be purified.

There are several plans by which these general features are observed, in the construction of cold storage houses, some of which have been made the subject matter of patents. The plans shown in the illustrations embrace the essential features of good cold storage construction. These plans do not conflict with any patented devices, and will prove adequate for all practical purposes.

THE GENERAL ARRANGEMENT OF COLD STORAGE HOUSES may be, as shown in the illustrations, Figures 67–70, for any size. Large houses require a girder and posts under the center of the ice floor, and the air flues are best made double; one set at each side, with a drain on each side of the girder along the center of the room. The construction of the walls vary. Walls filled with sawdust, charcoal, tan bark or other non-conducting materials, have been in use for many years. Carefully conducted tests, however, have conclusively proved that a wall of this description is inferior to a wall which contains dead air spaces, felt or paper linings, a section packed with mineral wool and an outer circulating air space.

The wall shown in Fig. 69 gives good satisfaction. It comprises air spaces, _A_, which are open to the outer air at the sill, and at the top open into the loft under the roof. Dampers _D_, in Fig. 68, are placed at the bottom, so they can be closed when desired. The next section, _B_, Fig. 69, is of dry sawdust, packed in place between walls of matched boards; the outer surface of these walls is lined with prepared water proof paper. The inner section, _E_, contains dead air spaces, which are about twelve inches square. The inner wall is of matched lumber and the outer one is of weather boards.

This construction keeps the sawdust dry, and the walls are free from dampness. The circulation of air through the outer air spaces carries off the heat imparted to the weather boards by the direct heat of the sun. When the air is humid, or charged with moisture, these air channels are tightly closed. The thickness of the walls may be varied with the capacity of the building. Additional sections of filling and dead air are required for large houses where large quantities of goods are refrigerated. Fig. 67 shows the ground floor.

The cold storage house shown in the illustration (Fig. 70) will hold forty tons of ice, and do all the work required for dairy, fruit and domestic service on a large farm with one filling of ice. By regulating the dampers, _D D_, Fig. 68, the circulation can be adjusted to meet all conditions. When these dampers are closed the ice wastes very slowly. The waste water, from meltage, is useful for cooling milk, and the milk room and cooling vats can be placed alongside the storage house or made a part of the same building to advantage.

A CREAMERY ICE HOUSE.--A very conveniently arranged and completely appointed creamery is shown in illustrations No. 72 and 73. Fig. 72 is a perspective view, and Fig. 73 the plan of a combined creamery, ice house and water tower. The tank _B_ is placed in the second story of the tower; _C_ is the ice house, _D_ the creamery. At _I I_ are set creamers, which are supplied with water from the tank by pipes passing through the ice house to cool the water. At _G_ is a churn, which may be run by power located in the annex _E_. At _H_ is a butter molder, and _J_ is the veranda.

By raising the ice chamber, a cold store room can be secured below it. If the structure is placed on an elevation, water from the tank can be piped through the dwelling house.

COMBINED DAIRY, COLD STORAGE AND ICE HOUSE.--Such an arrangement is shown in illustrations, Figs. 74 and 76. There is no communication between the dairy and storage room. For securing ice for the tank, double doors, made to fit very tight, are set in back of the ice chamber in the loft over the dairy. As leaving this door ajar would rapidly waste the ice, it should be under the care of a competent person and properly secured.

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.

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.

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.

A VERY CHEAP ICE HOUSE, but constructed on the same principles as those laid down in Chapter IV for commercial ice houses, may take the form suggested by Figs. 79, 80, 81, or any desired modification thereof.

A STILL SIMPLER DEVICE.--Where the expense of an ice house is not warranted by the small use to which it may be put for cold storage, on some farms, a supply of ice sufficient for household purposes can be placed in any convenient corner of a barn or other building. A room partitioned off with rough lumber, and walls, as well as floor, well insulated with non-conducting filling, will answer, and repay its cost many times over during the summer. In Fig. 82 is a view of an ice room built into a corner of a barn in this manner.

An above-ground silo, if built of wood, with double walls and air spaces, will make a most excellent ice house, if provided with double doors. The underground, or masonry silo, should be boarded up, with joists between walls, and boards to form an air space, if used for ice.

A LITTLE ORGANIZED CO-OPERATION in any farming community where ice-cutting privileges exist, will secure an abundant supply of ice for all purposes for the entire section or neighborhood. It is customary to do the threshing in turn, and all participate in the use of the threshing machine and power, where only very extensive farmers find it profitable to have an outfit for their own exclusive use.

In a similar manner the benefits of cold storage can be obtained. The houses can be owned by individuals, or by a few families who may be living near enough together to conveniently use one in common. The tools and outfit for cutting and handling the ice can be owned by a few enterprising young men, who can fill a large number of houses yearly by contract; or the appliances can be the joint property of all those having cold storage houses, who may combine to secure them, and also combine their labor in securing the ice crop. This work is done when the ordinary duties of the farm are light, and other interests would not be interfered with.

The practical advantages of this plan will readily present themselves to observing minds. An outfit of tools necessary to harvest, in good shape, one hundred tons of ice, will just as well harvest ten or fifteen times this quantity, and would really secure the larger quantity to better advantage than the smaller one. But, allowing that the labor in getting out one hundred tons of ice is the same per ton that it is for one thousand tons, the cost of the tools per ton of ice harvested is only one tenth as much in the latter case. The tools are durable, and will last many years. Ice plows which have been in use for fifteen or twenty years are still doing good service.

As the cold storage houses would be situated at several places, a brief outline of the methods in use for handling ice under similar circumstances, will be of interest. The ice is transported from the water to the houses by wagons or sleds. A platform is built near the edge of the water, in an easily accessible place, of a height a little above the bed of wagon boxes when they are backed up to the platform. The end of this platform is toward the water, and the teams are backed in on both sides. From the water end an inclined way or run is built down into the water. Upon this run the ice cakes are rapidly run up on the platform, quickly loaded on the wagons, and started on their way to the storage houses. Arriving at its destination, the load of ice may be deposited on the ground at the entrance of the house, and the team returned for another load. Meanwhile two men, with the assistance of a horse, can stow the first load in place in the ice chamber.

For such work the tools required on the ice field comprise:

One ice plow with guide. One ice saw. One ice chisel. One ice floating hook, twelve to twenty feet long. Three ice hooks, short lengths. One jack grapple. Two pairs of loading tongs.

At the ice house are required:

One pair hoisting tongs. One pair drag tongs. One pair edging tongs.

At this time the cash value of these tools is about sixty-five dollars for first-class goods, which are always the cheapest.

COST OF ICE IN THE HOUSE.--Regarding the cost of ice when stowed in place in the ice chamber, it would be difficult to quote an amount which would cover all cases. Locality and tact have much to do with determining this cost. Ice, twelve to sixteen inches thick, cut in small quantities and placed in the ice chamber, would cost, on an average, for labor, about fifty cents per ton. Where cut on a large scale the cost for labor in cutting and stowing is less than half of this amount.

A LOADING PLATFORM is illustrated in Fig. 83, which shows the method of running the ice cakes up with a jack grapple. The size of the platform is determined by the quantity of ice to be handled over it. One horse and grapple will readily serve several teams if a supply of ice cakes is maintained at the foot of the incline. Where many teams are to be served and the ice must be handled rapidly, two grapplers, one right and one left hand, can be used on the incline. By having the rope continuous and a pulling post at each end of the horse walk, the horse will pull a load each way, and several hundred tons of ice can be landed upon the platform in a day’s run. Where the incline is long a team can be used to advantage on the grapple rope.

A sweep such as shown in Fig. 85 is a convenience in handling ice cakes directly from the water to sleds or wagons where only a small quantity is wanted, and where the ice platform is not required. A similar device, which has the advantage of being more readily moved, is shown at Fig. 86. Where an artificial pond is made with an embankment, a loading platform may be constructed, as shown in Fig. 84.

IN PACKING THE ICE into the ice chamber, attention is required to prevent any dirt from adhering to the ice and being packed into the ice chamber, where it will accumulate in the drains and on the floors as the ice melts.

At _S_, in Fig. 68, will be found an opening over the drip pan; through these openings, placed at convenience along the back of the floor, the floor can be flushed with water and washed clean.

Time, labor and convenience are all conserved by the use of such necessary tools as are listed on previous pages. More can be added as the amount of ice cut is increased.

THE ICE FIELD should be kept free from snow by scraping from time to time. For clearing the small surface from which a harvest of forty tons can be secured, a simple scraper, cheaper than those used on large fields, will answer the purpose. An oak plank one and one-half inches thick, ten inches wide and six feet long, with two holes four inches from the bottom edge, and four feet apart, and a foot board mortised through the center, will do tolerable work. An iron shoe on the lower edge adds materially to its efficiency. Fig. 80 illustrates a scraper of this pattern.

Thirty-six cubic feet of ice weigh a ton. Hence, a surface six feet square on an ice field, where the ice is a foot thick, represent a ton of ice. At this rate a surface thirty-eight feet square would represent forty tons of ice. Owing to loss by breakage, and irregular cutting, it is usual to allow a considerable margin, greater in small than in large quantities, and a surface fifty feet square would readily harvest forty tons of twelve-inch ice. Where the ice is thinner a correspondingly larger surface is required to secure the same weight of ice.

The surface being cleared of snow, the ice plow is set upon the ice alongside a line drawn taut in the direction in which the plowing is to be done. The ice plow, drawn by hand and guided to run parallel with the line, gives the base groove. The blade of the guide is placed in this groove, and the field is now grooved in uniform spaces in one direction. The plow makes only one cut in each groove, while the guide is attached to it. By repeating this method grooves are made crossing those first made at right angles. The guide is now removed from the plow, and by plowing back and forth the ice is grooved to the depth desired, about seven or eight inches for twelve-inch ice and two inches for six-inch ice.

A channel is now opened at the foot of the incline, and a few hours work for four men, and a boy driving the horse to run the grapple, will land the ice cakes on the platform.