What is the term used for the region within an occupied space that is located between 3 and 72 inches above the floor?

The term that describes the region within an occupied space located between 3 and 72 inches above the floor is known as the "breathing zone." This area is critical because it represents the space where the majority of occupants' breathing occurs, thereby directly influencing the quality of air they inhale. Understanding the breathing zone is essential for HVAC design and air quality management, as it helps in determining how to effectively distribute air and maintain a comfortable environment for occupants.

This concept is foundational in both mechanical and environmental engineering, as it highlights the importance of air circulation and pollutant control at a level where people are present. Properly assessing and managing the conditions in the breathing zone is vital for ensuring health and comfort in indoor environments.