The Most Familiar Type of Air Conditioning

One reason human beings can thrive in all kinds of climates is that they can control the qualities of the air in the enclosed spaces in which they live. Air conditioning is the use of mechanical systems to achieve that control in such places as homes, offices, theaters, institutions, factories, airplanes and automobiles. The most familiar type of air conditioning is summer time cooling. Although important, this is but one of the several aspects of air conditioning. Other applications include the control of humidity( of air moisture), circulation of the air, and heating. It is also desirable that an air conditioner remove dust, pollen, smoke and odors from the air.

In many industrial environments, air conditioning is essential. Most print shops, for example, require constant humidity in order to control paper shrinkage. Libraries, especially one with rare books, require air control to preserve the physical quality of their collections. Bakeries and the tobacco and cotton industries require high humidity for their products, and perishables such as fruits must be stored in cool, dry rooms. Some electronic components, drugs and chemicals must be manufactured where the air is as free as possible of dust and other particles. Air conditioning is also vital in hospitals, especially in operating rooms.

There are several ways to classify air conditioners. It is note-worthy that the functions of all air conditioners are essentially the same. Nearly all of them cool and clean the air while they ventilate the space. Some humidify, dehumidify, and heat as well. Air-conditioners customarily cool by blowing the air through a coil of tubing that contains a cold fluid. The fluid, usually a special chemical, is most often cooled by the process of refrigeration. The air is usually cleaned by passing it through a filter. Dry filters in particular, work like a kitchen stainer, capturing impurities while clean air passes through.

Most people tend to group air-conditioners on the basis of size and complexity. For example, the familiar boxy device, commonly referred to as a room or window air conditioner, is also called a self- contained air conditioner. This is because all of its working parts are in a single unit. Some homes and buildings have central air conditioners. These have their controls in one area and the machinery in another. Systems in hospitals, factories or other large buildings may perform several functions at once in widely separated areas. These large air conditioners often controlled by computers, are properly called environmental control systems.

The amount of cooling produced by a home air_conditioner compared with the electricity it consumes is its energy efficiency ratio( EER). The higher the EER, the more efficient the air conditioner is. Air conditioners with an EER of 7.5 or higher are the most efficient and the best to buy. They cost more initially but cost less to operate and are thus 'money savers' in the long run.

The size of air-conditioner required for a given job is best determined by calculating a cooling load- that is, the amount of cooling that the machine will have to put out to condition the space. Cooling load depends upon the size and shape of the space; the number and size of windows and their orientation toward the sun, the areas of walls, ceilings, and floors and the extent to which they are insulated; local climatic conditions, the wattage of electrical equipment present and the number of people who normally occupy that space.