Which equipment forms a shield to exclude drafts while preventing hot air and dust from entering a building?

The chosen equipment, an air curtain, is designed specifically to create a barrier of air that serves multiple functions, including the exclusion of drafts, dust, and other outside elements from entering a building. By directing a continuous stream of air across the entrance, an air curtain effectively prevents the mixing of air from inside and outside spaces, maintaining a more stable indoor environment.

This is particularly useful in commercial buildings where doors are frequently opened and closed, allowing for easy access while still minimizing the influx of unwanted outside air. Additionally, air curtains contribute to energy efficiency by reducing heating or cooling losses, as they allow for doors to remain open without compromising internal climate control.

In contrast, the other options do not fulfill the same function. An air sweeper is typically associated with cleaning services, focusing on moving debris rather than air control. Mechanical exhaust refers to systems designed to remove air from a space without creating an air barrier, which does not prevent drafts or the entry of outside air. An air conditioning unit (ACU) is primarily used for temperature regulation and comfort, but it does not create a barrier to protect against outside elements in the way an air curtain does.