Air conditioner

In 1900 there were very few people who could do during a heat wave, except complain about the weather or, if they could afford it, go to the mountains or the seashore. Today air conditioning has changed this. With air conditioning this has changed. With air conditioning, you can be comfortable anywhere indoors, even on the hottest, stickiest day of the year. You will surely find air conditioning in the movie theaters you attend, in many of the stores where your family buys, and in the restaurants where you eat. You can even be in your own home.

What is air conditioning?
You know that air conditioning makes you feel good. But air conditioning is more than just cooling. It means keeping the temperature and humidity (moisture content) of the air in a closed space, whether in a room or in an entire building, at the right level for the comfort of the people inside. It also means circulating air and adding moisture if necessary. In summer it means stirring the air over cold pipes that collect water from the air, in the same way that water droplets condense into a glass of cold water on a hot and humid day. In fact, we could almost say that air conditioning means creating an artificial and comfortable climate. In this article we will discuss only cooling.

In dry climates, the air can be simply cooled. The refrigerator can be no more than a big fan that draws hot, dry air into a water-soaked fiber mat. The air is cooled by evaporating the water. For starters, it is dry, as the added moisture will not cause discomfort. (This is not the case in humid climates)

Air conditioning has many uses in addition to keeping us comfortable. Many industries rely on it to keep the air in their plants clean, fresh, and at the right humidity. For example, textile fiber like wool and cotton will stretch or shrink as the moisture content of the air changes. This causes variations in the quality of the fabric. Too much moisture in the air, or even on the tip of a worker's fingers, will cause corrosion of delicate metal parts, such as rocket components or precision instruments. The wrong temperature can spoil a batch of antibiotic culture. Adequate air conditioning avoids this setback.

South Africa's deep diamond and gold mines use air condition to allow miners to work in what would otherwise be stifling in the heat thousands of feet underground. Air conditioning intervenes in every part of the United States space program, from missile manufacturing to tracking it through the atmosphere.

Inventors have played with air conditioning methods for years. The ancient Egyptians and Romans were relieved by the heat by hanging water-soaked woven mats at the entrances of their houses, so that the air would rot by evaporation. In the XV century d. C., the famous artist and inventor built a water fan.

As men's interest in science grew, so did the number of schemes for improvement. There were hundreds of ideas, but none of them really worked. In fact, many of the schemes made people feel worse because they added a large amount of water to the air. Air is like a sponge. It will absorb water and make people feel sticky and uncomfortable, especially in hot weather. When the air is very humid, we say that the humidity is high. When the air is dry, the humidity is low and we feel better.

The first machine that kept humidity low or cooled the air at the same time was developed in 1902 by Willis H. Carrier, who built it often called "the father of air conditioning." Carrier built this machine for a printing plant in Brooklyn, New York, which was having trouble printing in color. The paper stretches when the air is humid and contracts when the air is dry. Because each color had to be printed separately, printing different colors on the same sheet of paper did not align precisely because the papers resized between prints. Carrier's machine kept the humidity level of the air constant by dragging the air over a row of cold pipes that condensed excess moisture. This kept the paper in a single size and also made people on the floor feel great. Carrier's invention marked the beginning of scientific air conditioning.