History of Air Conditioning
If you think that the fight against heat and the use of cooling systems are relatively modern concepts, the beginning of this article may surprise you greatly. Let’s start by exploring the history of air conditioning, going all the way back to the ancient Egyptians—thousands of years ago.
The Battle Against Heat in Ancient Egypt
The ancient Egyptians already used certain methods to help pharaohs enjoy pleasant temperatures by reducing the heat in their chambers. The walls of the pharaoh’s palace were made of large stone blocks, each weighing over 1,000 tons.
How Did the Egyptians Cool the Pharaoh’s Palace?
At night, thousands of slaves were tasked with dismantling the walls and transporting the stones to the Sahara Desert. In the desert, temperatures at night were very low due to the extreme desert climate.
The stones would cool quickly, and before sunrise, they were brought back to the palace and reassembled. This way, during the day, the pharaoh could enjoy temperatures close to 26°C, significantly lower than the outside temperature, which was nearly twice as high.
The Principle of Air Conditioning
This crucial moment in history is often overlooked. In 1842, a man named Lord Kelvin invented what could be considered the foundation of air conditioning.
This scientist worked on a system that could create a comfortable environment by developing a hermetically sealed refrigeration system that used a refrigerant gas to absorb heat from the air.
What Principles Did This Invention Rely On?
This early air conditioning system was based on three principles:
- Heat always moves from hotter areas to cooler ones. For example, if you place a spoon in hot coffee, the heat transfers from the coffee to the spoon, making it warm.
- When a liquid turns into gas, it absorbs heat. You can see this at home if you put alcohol on your hand. As it evaporates, you’ll feel a cool sensation because it absorbs heat.
- Temperature and pressure are related. In closed containers, less heat is needed to reach the same temperature. Think about a pot on your stove—when it’s covered, the contents heat up faster than when it’s open.
The Beginning of Modern Refrigeration
This is often considered the true origin of air conditioning, at least as we know it today. It all began in the early 20th century, specifically in 1902.
In that year, an American named Willis Haviland Carrier laid the groundwork for modern refrigeration. Initially, he developed his technology to solve problems caused by excessive humidity in cooled air, creating and refining the concept of summer air conditioning.
It all started because Carrier wanted to help a printing business owner in Brooklyn, New York. This businessman was facing issues during the printing process due to constant changes in temperature and humidity, which caused the paper’s dimensions to change slightly. As a result, the ink wouldn’t align properly, leading to poor print quality.
Carrier began researching ways to solve this problem and soon designed a machine capable of controlling both humidity and temperature through a series of cooling coils. This machine is considered the first air conditioning unit.
This invention solved the printer’s problem, allowing him to print in four colors with ease. In 1906, the invention was patented as an air treatment device since the term “air conditioning” wasn’t used