In the scorching heat of summer, we all need a cool breeze to live comfortably. Thankfully, we have the air cooler, a remarkable invention that brings us much-needed relief. But have you ever wondered who came up with this ingenious solution to beat the heat? In this blog, we will uncover the story of the air cooler's invention. So, let us dive in and learn who invented the air cooler.
Who Invented Air Coolers?
The invention of air coolers happened due to the need for cool air. Its need gave rise to numerous innovations throughout the course of history.
- Innovations during the ancient Egypt
Frescoes and plaster paintings dating back to 2500 B.C. give a glimpse into early efforts to combat the heat. Slaves were depicted fanning jars of water to cool rooms for royalty. This marks the beginning of an archaeological trail leading to the integration of evaporative cooling mechanisms. These mechanisms included water ponds, pools, thin water chutes and porous water pots fixed into thick-walled and shaded enclosures.
- Middle-age ingenious solutions
With the advent of the Middle Ages, individuals used water-soaked cloths, suspended over open windows for cool air. The warm outside air, flowing through these moistened fabrics, brought relief to the interiors of homes that lacked the protective shield of glass.
- Advent of Mechanical Cooling and Further Advancements
As time moved forward, many individuals and concepts contributed to the invention of mechanical cooling systems. These contributions spanned over centuries which ultimately led to the invention of air coolers.
- Leonardo da Vinci's invention
In the 16th century, Leonardo da Vinci crafted the first hygrometer, a device using a ball of wool to reveal the ambient humidity levels. Further, he ventured into mechanical air cooling. He designed a hollow water wheel to guide air from the wheel to the living space. As the water wheel splashed and evaporated water, it started cooling the air in the process. The motive for this invention came from the water turning a partially submerged wheel. As sections of the wheel dipped into the stream, the compressed air rushed through passages, creating a flow of cool air.
- Pascal, and Boyle’s contribution
Fast forward to the 17th century, Blaise Pascal's rule emphasised that pressure exerted on a confined liquid is transmitted uniformly. On the other hand, Boyle established the inverse relationship between the volume of dry gas and the pressure exerted on it when the temperature remains constant. These concepts influenced the science of evaporative cooling.
- Concept of fluid dynamics
Enter the 18th century, a time when scientific minds like Bernoulli, Euler, Pitot, and Chézy applied the techniques of mathematical physics. Their concepts gave birth to the science of fluid mechanics. Meanwhile, John Dalton contributed by explaining the nature of evaporation and its role in the global cycle.
- Darcy's insights
In the 19th century, Darcy's groundbreaking work offered a profound understanding of air flow through porous materials. This discovery became an essential aspect that contributed to the evolution of cooling systems.
- Early innovations in the 1920s and 1930s
In the 1920s and 1930s, settlers in the Southwest America devised creative ways to beat the summer heat. Screened porches, roofs, and outdoor spaces became bedrooms, with wet sheets offering some relief. Reports from the Arizona Republic describe guests at the Ford Hotel in Phoenix sleeping on balconies while young men peddled to power overhead fans.
- Birth of modern evaporative cooling
The modern era of evaporative cooling had its origins in the early 1900s. During this time air washers were invented on the East Coast and air coolers developed in the Southwest, specifically Arizona and California. Air washers cleaned and cooled air in textile mills and factories in the East. Southwestern air coolers come in two types: indirect coolers, passing air over a water-cooled coil, and direct coolers, cooling air through direct water contact.
- Early designs and evolution
The earliest direct coolers featured wooden frames covered with wet burlaps with fans forcing air into the cooled space. Evolving over time, sumps and recirculating pumps were integrated into designs. However, scale formation on pads led to water discharge or bleeding. The design further evolved to the familiar configuration of two-inch pads sandwiched between chicken wire. These designs are also known as wet-boxes, desert coolers, drip coolers, and swamp coolers.
- Public demonstration and improvements
The first demonstration of an aspen pad (swamp) cooler took place on June 20, 1916, at the Adams Hotel in downtown Phoenix. In 1939, Martin and Paul Thornburg, professors at the University of Arizona, published instructions to enhance the performance of direct evaporative coolers. This marked a turning point as mass production of evaporative coolers began with integrated motor and fan units from Emerson Electric Company.