History of Air Cooling
When you pick up an air cooler, you’re picking up something with thousands of years of history! People have been using them in one form or another for thousands of years, and while they’re much more modern now, the principles of how they work are still the same. The story of the air cooler is a surprisingly glamorous one involving Egyptian Pharaohs, brilliant scientists, and even Leonardo da Vinci!
Early Air Cooling
Evaporative cooling occurs in nature over puddles, lakes, oceans, and any other body of water, so it’s been around for a lot longer than humans have! The (very) simple explanation of it is that when water evaporates into the air, some of the heat in the air is lost. We’ve been using this natural process to keep cool for longer than many people realise. The earliest evidence we have is from ancient Egypt, dating from around 2500BC – stone tablets from this time show pictures of slaves fanning pots full of water to keep their wealthy masters cool. The Egyptians would also design buildings incorporating ponds, water pipes, pots, and porous (water-absorbing) clay walls to make use of evaporative cooling, so you could say they had the first air-conditioned homes!
The Invention of the Air Cooler
Primitive evaporative coolers like these continued to be used in hot countries throughout the ages. Greeks, Romans, and Persians would all use evaporating water to add a chill to hot, dry air. Roman emperors would go one step further and order expeditions into the mountains to bring down snow and ice to cool their homes. However, the first mechanical air cooler wasn’t invented until the 16th Century by – who else – Leonardo da Vinci.
His air cooler was automatic and only needed some running water to work. It consisted of a hollow water wheel with an air passage inside it. As the wheel turned, the water would splash up and evaporate. The air passage inside the wheel acted as a sort of pipe which would guide cool air from the evaporating water into vents so it could be directed into rooms around the home. As you can imagine, it wasn’t exactly as lightweight and portable as the models you’ll find on this website, but it was a big step towards air coolers as we know them!
Understanding Air Coolers
We didn’t really understand how air coolers worked yet – we just realised that water makes things cool. This limited how much we could develop them. It wasn’t until the 17th and 18th Centuries – when the Enlightenment period was in full swing – that we really started to think about how it all worked. Our understanding of fluid mechanics improved a lot during this period which led to a breakthrough called Dalton’s Law. This was when the English scientist John Dalton observed that the rate of evaporation was increased by the temperature of the water, the wind speed flowing over the water, and low atmospheric pressure.
In basic terms, this breakthrough meant people were now aware that blowing air at high speeds across a body of ice or water led to a greater chill.
Perfecting the Formula
Now that people understood the basics behind air coolers, we started coming us with all sorts of inventions to try and get the formula just right. Most notable was a strange invention by the Englishman William Whiteley. He had the idea of placing a tray of ice and a fan beneath a horse carriage, with the fan connected to the axle. As the carriage moved, the fan would spin and blow air over the ice tray and into the carriage. You could say this was the first air-conditioned vehicle!
Air coolers as we know them today weren’t really possible until the invention of the electric fan. The idea of using an electric fan to blow cool air through a damp sheet became popular in parts of America through the 1920s, especially in southern swamps and desert regions. The earliest air coolers were homemade, and consisted of an electric fan placed inside a wooden frame with a damp piece of fabric nailed to it. These units were small, relatively portable, and very effective, and became the blueprint for all electric air coolers to come – including the ones on our website!
These primitive air coolers – also known as swamp coolers or desert coolers at the time – were much more effective than anything that came before, but there was still room for improvement. Businesses and inventors picked up on the idea and gradually started to improve the design. What started as a piece of wet cloth draped over a frame was soon fitted with water pumps and a tank to continually cycle water around the system, making the cooling effect last for longer. The piece of fabric was soon replaced by a more absorbent material made from aspen wood chips, and was sandwiched between two pieces of wire mesh to prevent it from sagging. This was so effective that you can still find air coolers using aspen pads today, although modern models use more advanced honeycomb-patterned pads. Wooden frames soon gave way to more durable and lightweight plastic housing. The modern air cooler had arrived!
By the early 1950s, air coolers were big business. Designs and production processes had improved so much that companies across the world were able to churn out new models on a regular basis, with each design better than the last. Nowadays, most air coolers use advanced pump systems and more durable synthetic material for better performance and a longer lifespan. The pumps ensure the fabric stays damp without absorbing too much water and sagging. They also mean that the pad absorbs water evenly, which is important to prevent mould growth.
When you pick up an air cooler, you can buy with confidence that it’s a tried-and-tested design that’s been refined over thousands of years! Modern models are very small and lightweight but are precisely-engineered to give you the most efficient heating performance.