Air Curtain

air curtain [′er ‚kərt·ən]

(mechanical engineering)

A stream of high-velocity temperature-controlled air which is directed downward across an opening; it excludes insects, exterior drafts, and so forth, prevents the transfer of heat across it, and permits air-conditioning of a space with an open entrance.

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air curtain

air curtain or air door

A stream of high-velocity temperature-controlled air which is directed downward, across an opening; excludes insects, exterior drafts, etc.; prevents the transfer of heat across it, and makes it possible to air-condition a space having an open entrance; used in exterior doors, on loading platforms, etc.

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Air Curtain 

a device in a local forced ventilation system for preventing the entry of cold outside air into an industrial space through open doors (or gateways) in industrial and commercial buildings. It consists of ducts with linear slots through which air is delivered by a fan with a velocity of 8-20 m/sec at an angle of 30°-45° to the face of the opening, against the stream of air tending to penetrate into the premises. Air curtains are also used at the enclosure openings of industrial equipment (to prevent the escape of hot, contaminated air into a room space) and in other cases where it is necessary to block off a current of air through an opening. The air supplied by the fan is often preheated; this type of unit (when used with an air preheater) is called a heated air curtain.