In 1900 there was very little people could do during a hot spell except grumble about the weather or -if they could afford it -go away to the mountains or the seashore. Today air conditioning has changed this. With air conditioning has changed this. With air conditioning you can be comfortable anywhere indoors on even the hottest, stickiest day of the year. You will almost certainly find air conditioning in the movie theaters you attend, in many of the stores where your family shops, and in the restaurants where you eat. It may even be in your own home.
What is air conditioning?
You know that air conditioning makes you feel cool. But air conditioning is more than just cooling. It means keeping the temperature and humidity (moisture content) of air in an enclosed space, whether it is one room or an entire building, at just the right level for the comfort of the people inside. It also means circulating the air and adding moisture if necessary. In summer it means removing by passing the air over cold pipes that collect water from the air, much as drops of water condense on a cold water glass on a hot, damp day. In fact, we might almost say that air conditioning means creating an artificial, comfortable climate. In this article we shall discuss only cooling.
In dry climates air can be cooled simply. The cooler may be no more than a large fan that draws hot, dry air to a water soaked fiber mat. The air is cooled as it evaporates the water. It is do dry to begin with that the added moisture will not cause discomfort. (This is not the case in humid climates)
Air conditioning has many uses besides keeping us comfortable. Many industries depend on it to keep the air in their plants clean, cool and at the right moisture level. For example, textile fiber such as wool and cotton will stretch or shrink as the moisture content of air changes. This causes variations in the quality of the cloth. Too much moisture in the air -or even on a worker’s fingertips- will cause delicate metal parts such as rocket components or precision instruments instrument to corrode. The wrong temperature can spoil a batch of antibiotic culture. Proper air conditioning prevents this mishap.
The deep diamond and gold mines of South Africa use air conditioning to enable miners to work in what would otherwise be suffocating in heat, thousands of feet below the ground. With the air conditioning is involved in every part of the United States space program, from making missiles to tracking them through the atmosphere.