Air conditioner: who invented it??

The history of the air conditioners on the principle of action, which is widely used now, is connected with the name of the American engineer Willis Carrier. It is his name that Carrier’s popular modern air conditioners are named after.

The air conditioner was simply a “refrigerator in reverse.”

It all started when the owner of a print shop in Brooklyn, New York, complained about the high humidity and heat in the print shop, which made the ink smudge on the paper. He was concerned about how to lower the humidity in the print shop.

Young engineer Carrier decided to use a physical law to solve this problem – when the air temperature drops, its humidity decreases.

Carrier was familiar with the design of industrial refrigeration machines and in a short period of time he built an electric apparatus that housed coils cooled by a refrigeration machine. It was in 1902.

Carrier’s first installation reduced the humidity in the print shop by 55%. “Air treading machines,” as Carrier mysteriously called them, were installed to dry the air in cotton spinning, textile, and pasta mills.

Soon a textile engineer coined the term “air conditioning” because the concept of “air conditioning” was used in the processing of yarn and fabric. And only later it was noticed that the new apparatus not only dehumidifies the air but also cools it. That one is over a hundred years old.

In 1929 Carrier developed household air conditioners for cooling and dehumidifying the air in private homes. New designs of apparatuses with reduced dimensions and power were created.

At the same time, Carrier began installing air filters in his air conditioners. Then came the function of warming the air, and so on.

But the operating principle that Carrier used in his first unit in 1902 remains unchanged today. And this principle is the same as that of a domestic refrigerator.

Nevertheless, even technically literate people often show lack of understanding, and from it follows mistrust and many prejudices.

Here’s how an air conditioner, which can be called a “refrigerator in reverse,” works.

When operating in cooling mode, a fan draws air from the room through an air filter into the interior compartment and cleans it of dust. The superheated refrigerant freon, compressed by the compressor, meanwhile, enters the condenser, a long zig-zag tube.

Here it partly gives its warmth to environment outdoors . After passing through the expanding valve, the freon pressure drops sharply, it enters the evaporator where it boils and evaporates, turning into a gas.

It takes a lot of heat energy to evaporate. It is extracted from the air that washes over the evaporator and part of the moisture condenses on the evaporator. The cleaned, cooled and dried air goes back into the room.

The heat, extracted from the air, is carried away by freon that circulates in the coil condenser and is expelled outside the building. The evaporated freon is sucked in again by the compressor and the cycle repeats.

And also about the kinship of a fridge and a conditioner. There is a widespread anecdote about Chukchi: “Why do they buy refrigerators??! And then to get warm in them: it’s -40 degrees outside, and the refrigerator is +4!”.

Actually, a fridge can only create a given temperature difference downward and is not capable of providing a temperature higher than the outside temperature in the refrigerating chamber. It takes out the excessive heat from the refrigerating chamber and blows it out.

From the point of view of physics the joke is wrong but witty. But an air conditioner is a “inside out” refrigerator, a heat pump, which extracts heat from outside air and transfers it inside the house in strict correspondence with the Carnot cycle studied at school ! .

Even if the temperature outside is sub-zero, there are plenty of calories in the air compared to the absolute zero of outer space. So the chukchi can really get warm from the refrigerator if it’s running “backwards”. Most modern air conditioners can pump energy in two directions: both for cooling and heating.

Is it true that air-conditioners cool the air??

That’s not the whole truth. If to look in the English-American dictionary, the word “to conditin” means: to bring in desirable, necessary good condition. In short, to condition the air in the room.

It is not uncommon for the air in a building to be too warm or too cold, too humid or too dry. The air can be contaminated with dust, pathogenic bacteria, allergens, mold spores. All these things are very bad for our health.

A modern air conditioner is designed to bring the air we breathe indoors into a “conditioned state” according to all of these indicators.

Since 1902, when the first apparatus was created that performed only the function of dehumidifying air, the air conditioner has gradually acquired new functions. By 1958, it could cool, dehumidify and purify the air with filters.

In 1958, the first air conditioner, capable of working both in cold and heat mode, was made. Here is the fourth function: heating of air, if it is necessary. The newest generation models also have an air ionization function, the fifth.

And now there are more and more models that can enrich the air with oxygen. This is the sixth function. The most advanced companies produce air conditioners with sensors of carbon dioxide in the air and with the function of removing the excess CO2. Here’s feature number seven.

Besides, any conditioner can work as a fan. This is another function, the eighth. In a word, modern air conditioner replaces the whole set of climatic equipment for air treatment and improvement of our homes ecology.

So, the statement that air-conditioners only cool the air, initially did not correspond to the reality.

That it is necessary conditioner only in a hot season is also a delusion. For example, in Scandinavia with its cool climate and short summer almost all offices and many dwelling houses are equipped with air conditioners. They serve not so much for cooling air as for creation of comfortable microclimatic conditions in the premises all the year round.

Nowadays it is not enough that conditioners simply cool or warm air. They have to be able to: provide the optimum temperature comfortable humidity clean and mobile air quiet operation a high degree of reliability easy maintenance and run a wide range of special programs. Besides air conditioners should ideally blend in the interior of the premise.