When air flows out of an area upon opening a door, what type of airflow is occurring?

In the context of airflow dynamics, when air flows out of an area upon opening a door, this indicates that the pressure inside that area is lower than the pressure outside. This scenario is referred to as negative airflow.

Negative airflow occurs when the air pressure inside a space is less than the air pressure surrounding it, leading to air being drawn out of that space when a door is opened. This phenomenon is important in various settings, particularly in sterile processing environments, as it helps to ensure that contaminants from outside do not flow into sterile areas.

Positive airflow, on the other hand, would describe a situation where air flows into an area due to higher internal pressure, which does not apply in this case. Neutral airflow would indicate that there is no significant pressure difference between two spaces, and directional airflow refers specifically to a controlled movement of air in a particular direction, which also does not fit the described scenario of air flowing out when the door opens.