Aka Air Door – a sheet of moving air blown downward in a doorway or other opening and used for separating two spaces from each other. Air curtains can heat the air with or without the use of an actual heater but the stream is produced by one or more fans. It is an inexpensive method in which to protect the inside of a building from the elements on the outside (insects, rain, dust) as at the same time as keeping the opening free for traffic yet works most effectively when the pressure or temperature between the two spaces are fairly neutral. Most Air Curtains are vertical but can also be horizontal.
Vaneaxial fans, FC Centrifugal fans and Cross-flow blowers are used in the production of Air Curtains.