An air door, sometimes called an air curtain, employs a controlled stream of air aimed across an opening to create an air seal. This seal separates different environments, while allowing a smooth, unhindered flow of traffic and unobstructed vision through the opening. Because air doors help to contain heated or air conditioned air, they provide sizeable energy savings and personal comfort when applied in industrial or commercial settings (stores, supermarkets, banks, restaurants, depots, factories, warehouses ,hospitals,airports, and so on). Air doors can also be used to stop the infiltration of flying insects,dusts,smokes and odor.