Air curtains, also known as air doors, have a long history dating back to the early 1900s. The concept of using a stream of air to create a barrier between two different environments was first introduced in the form of the revolving door. However, the revolving door had several limitations, including its high cost, complex design, and limited application.
In the 1920s, the first air curtain was invented by Theodore H. Kesselring, an engineer at the American Air Filter Company. The air curtain consisted of a blower and a series of nozzles that directed a high-velocity stream of air across a doorway. The air stream created a barrier that prevented the transfer of air, dust, and pollutants between the inside and outside environments.
During the 1930s and 1940s, air curtains gained popularity in the food and retail industries, where they were used to maintain temperature control and prevent the entry of insects and dust. In the 1950s, the use of air curtains expanded to other industries, such as hospitals and laboratories, where they were used to prevent the spread of infectious diseases and maintain a sterile environment.
In the 1960s, air curtains saw further development with the introduction of electrically heated air curtains. These systems provided improved temperature control and energy efficiency, making them popular in commercial and industrial applications.
The 1970s and 1980s saw continued innovation in air curtain technology, with the introduction of new materials, improved blower systems, and advanced control mechanisms. In addition, the development of computer modeling and simulation tools allowed for more accurate and efficient design of air curtains.
Today, air curtains are widely used in a variety of industries, including commercial, industrial, and residential applications. They are used to maintain indoor air quality, regulate temperature, and improve energy efficiency. With ongoing research and development, air curtains are likely to continue to evolve and become even more effective in the future.