10 curious facts about air conditioners you didn’t know

Cooling and air conditioning have been around for a very long time. Modern air conditioners have a history going back over a hundred years and we’ve seen all sorts of new innovations and improvements to new systems. Whether at home, at work, or in supermarkets, restaurants and hospitals, heating, ventilation and air conditioning (HVAC) equipment is an essential part of our everyday lives. But there may be a few other curious facts you may not know.

Here are ten interesting facts about air conditioning to whet your appetite:

Early artificial cooling started with chemical reactions

Before mechanical engineering, early scientists experimented with chemical reactions that caused cooling. In the 18th century, Benjamin Franklin and chemist John Hadley discovered that evaporation of liquid caused a drop in temperature, even below the freezing point. They tested different liquids with a mercury thermometer and found that water dropped in temperature when it evaporated. They also found that different liquids had different levels of cooling, depending on their volatility and therefore the rate at which they evaporated. Alcohol lowered the temperature much more than water, and highly volatile ether had an even stronger cooling capacity. But their experiments were done on small amounts of liquid and had no effect on room temperature. Nevertheless, they laid the foundations for artificial cooling.

Later, in the 19th century, Michael Faraday made more progress on these early discoveries; he began experimenting with ammonia and found that it could cool the air in his laboratory by first compressing and liquefying the ammonia, then letting it evaporate. Although ammonia is not used today because of its poisonous nature, it was a groundbreaking discovery that contributed to refrigeration as we know it today.

Ice blocks were the first air conditioners

During the 19th century, outbreaks of yellow fever and malaria were widespread in warmer regions of the United States, such as Florida. At that time, large blocks of ice were shipped from the northern states for use in hospital rooms to provide comfort to patients. Wealthy families would also use ice in their homes to cool off. But this method was tedious and expensive, so physician Dr. John Gorrie decided to take matters into his own hands. Through his efforts, he created an “ice machine” and in 1851 was granted the first US patent for mechanical refrigeration. Gorrie’s machine utilized a scientific principle still used in modern refrigeration; i.e. the rapid expansion of the gas causes cooling.

His invention allowed air to be condensed using two force pumps, the compressed air was then directed through coils under cooling water into a low-pressure reservoir, where it dropped the temperature below freezing. Thanks to this freezing reservoir, water was slowly dripped into molds to form ice cubes. A model of this revolutionary machine can be seen at the Gorrie Museum in Florida. Sadly, Gorrie was unable to bring his invention to market due to the death of his main investor and business partner; but it opened up the possibilities of modern cooling systems.

Modern air conditioning was invented to dry ink

Surprisingly, the first modern instance of an air conditioner was not invented for the purpose of cooling and human comfort, but to regulate humidity in a publishing house.

In the early 20th century, a publishing company commissioned engineer Willis Carrier to deal with a moisture problem in their building. The high humidity levels prevented the ink from drying completely, making it smudge, and also caused wrinkling and warping of magazine pages. He successfully created a humidity control system as requested; and, realizing the potential of his system, he later continued to work on his invention to improve and commercialize it, calling his system the “air treatment apparatus.” The fact that this system not only cooled indoor temperatures but also controlled humidity is what makes it most similar to modern air conditioners. This has rightly earned it the title of the “Father” of air conditioning.

The summer movie phenomenon started thanks to AC

Ever wondered why summer blockbusters are so popular? You might be intrigued to know that it’s all due to air conditioning.

Early modern air conditioners were large, bulky and expensive, so they used to be installed only in public and commercial spaces that could afford the investment. The first buildings to incorporate them were hospitals, government buildings and, more popularly, movie theaters and theaters. To escape the heat waves in the warmer months, going to movies and shows in cool comfort became a popular and affordable form of entertainment, bringing more revenue than ever to movie theaters and theaters in the summer.