As the development of human civilization weakened people¡¯s adaptability against environmental changes, people started to consider defensive measures to secure their living. In order to protect people¡¯s comfortable living from temperature changes, people had to increase energy expenditure. In addition to that, various environmental threats including atmospheric contaminants resulted from industrial development and became another stress to people.
To solve some of these issues, the air curtain was invented to reduce energy expense by preserving room temperature and to prevent the inflow of the atmospheric contaminants from the outside. It provides a comfortable indoor environment with economical maintenance as well.