The more commonly used term for an air door in North America is "air curtain." The concept may seem like a marvel of the modern age, where a vertical waterfall of air separates two distinct environments from one another with great precision. But this technology dates back to 1904. Theophilus Van Kannel received a U.S. patent for "Means for Excluding Drafts from Open Doorways," which described an air curtain. However, the first air curtain installation in the United States was not installed until twelve years after the patent was issued. Erling Berner brought advanced European air curtain technology to the United States in 1956 and formed Berner Industries, which later became Berner International.
Air curtains are commonly used where doors are required to stay open for operational purposes, such as at loading docks and vehicle entrances. Cold drafts can be avoided by mixing in warm air heated by the air door. They offer energy savings and increased personal comfort by maintaining interior temperatures and helping keep flying insects out by creating forceful turbulence. Modern air curtains are designed to perform their barrier function without hampering passage or creating obstructions that can lead to accidents.
Airflow through a door depends on wind forces, temperature and pressure differences. Air curtains and doors work best when the pressure differential between the inside and outside of the building is as close to neutral as possible. Negative pressures, extreme temperature differences, elevators nearby, or extreme humidity can reduce the effectiveness of air curtains.
Above is a 1960 advertisement from the American Air Curtain Corporation.
No comments:
Post a Comment