An Air Curtain, also known as an air door, is a machine that blows a controlled stream of air across an opening to the other side to create an air seal. This seal separates different environments while allowing a smooth, uninterrupted flow of traffic and unobstructed vision through the opening. Because they help to contain heated or conditioned air, they provide sizable energy savings and increased personal comfort when applied in industrial or commercial settings. They also help to stop the infiltration of pollutants and flying insects.