GilHG Nelson

Storage of Fruits and Vegetables

The market life of fresh vegetables and fruits can be extended by prompt conditioning and storage in a proper environment. The storage period varies from a few days to two weeks for apricots, green peas, and ripe tomatoes. For some other fruits and vegetables the safe storage period is considerably longer, up to 8 months for apples and potatoes.

Livestock Waste Management

The production of livestock with much larger herds confined and concentrated in smaller areas has created problems in handling and utilizing livestock wastes not encountered before. Protecting ground water from contamination and controlling noxious odors are also important considerations.

Principles of Crop and Food Preservation and Storage

The demand for food is continuous, but production is seasonal. Hence, preservation and storage of crops in such a way as to maintain maximum nutritive value is of utmost importance, especially in the underdeveloped countries in which, for example, a substantial amount of the food grains produced (from harvest to time of consumption) is lost due to the ravages of birds, rodents, insects, and microorganisms. These losses can be reduced if not avoided entirely by applying known successful methods of preservation and storage. The adoption of improved methods would help greatly to alleviate the food shortage in these countries.

Estimating Heating and Cooling Loads

The calculation of “heating and cooling loads” often is a borderline problem that lies between the design of buildings and that of equipment. The design of a heating system, for example, is a primary concern of the equipment engineer, but the size and type of equipment required are greatly influenced by the type of building construction. A similar situation exists with refrigeration and other installations involving heat exchange. This interdependence makes it desirable for the building designer to understand the relation between structural characteristics and equipment load.

Heat Flow Through Walls

In Chapter 1 the principles of heat transmission were developed on the basis of heat conduction through homogeneous materials and heat transfer from surfaces by radiation and convection. In actual construction the walls, ceiling, and roof enclosing a building space rarely are homogeneous. Usually each consists of a combination of different materials. Consequently, the practical problem is one of determining the heat transfer through such building components taking into consideration air spaces and surface conductances.

Drying and Cooling Stored Crops

Drying and cooling harvested crops is customarily treated with other subjects, such as crop processing, but certain aspects of this topic are so intimately related to environmental control for the preservation of crops in storage that it is not only appropriate but essential to include it here.

Moisture Condensation in Walls

Condensation on windows frequently is a nuisance, though not particularly harmful; but on wall or ceiling surfaces or in attic spaces it may prove damaging to the structure or its contents. Condensation within the walls may result in paint blistering and in severe structural damage. A condition favorable to condensation is a high relative humidity within the building. As this is a usual condition in livestock structures and in fruit and vegetable storages, the problem is of particular interest.