What term is used for air removed from a conditioned space and either recirculated or exhausted?

The term used for air that has been removed from a conditioned space and is either recirculated back into the system or exhausted outside is "return air." This air typically comes from living or working areas and is directed back to the heating or cooling system for treatment before being redistributed back into the space.

Understanding this term is essential for HVAC systems, as return air plays a crucial role in maintaining the indoor air quality and temperature of a building. It ensures that the system operates efficiently by enabling the necessary mixing of indoor air with fresh air, leading to a balanced and comfortable environment.

In contrast, exhaust air refers specifically to air that is vented out of the space without being recirculated, fresh air indicates the outdoor air that is brought into the conditioned space, and makeup air is the replacement air that is provided to an area to offset the exhaust air. Each of these terms has distinct meanings in the context of HVAC operations, making "return air" the precise answer to describe air that is recycled within the system.