An air curtain is a device that creates an invisible barrier of high-velocity air across a doorway or opening. This continuous stream of air separates indoor and outdoor environments, preventing the infiltration of unconditioned air, dust, fumes, and insects, while still allowing for unobstructed access.

Air curtains are commonly installed in entrances of commercial, industrial, and retail spaces where doors are frequently opened and closed. By maintaining the separation between different temperature zones, they help businesses improve energy efficiency, enhance comfort, and support better hygiene.