What is the term for a pipe or shaft used to remove foul or congested air from a fixture or room and convey it to the atmosphere?

The term that describes a pipe or shaft designed to remove foul or congested air from a fixture or room and convey it to the atmosphere is referred to as a venting pipe. This type of pipe plays a critical role in plumbing systems as it ensures proper air circulation, allowing sewer gases to escape and preventing pressure vacuums that can cause drainage issues. Venting pipes are essential for maintaining a healthy indoor environment and proper function of plumbing fixtures.

The other terms in the choices pertain to specific types of venting purposes but do not accurately represent the general function of removing air from a space to the atmosphere. Local vents typically refer to those that serve a single appliance or fixture. Crown vents and back vents have more specialized designs relevant to particular systems and circumstances within plumbing rather than the broad and foundational role of a venting pipe.