What is the primary characteristic of positive air pressure in a room?

• A. Air flows into the room from outside
• B. There is no air movement
• C. Air flows outwards because of higher pressure inside
• D. Air is filtered through a special system

Answer: (C)

The primary characteristic of positive air pressure in a room is that air flows outwards because of higher pressure inside. In a space with positive air pressure, the internal air pressure is greater than the external air pressure. This difference in pressure allows air to escape from the room when doors or windows are opened, effectively preventing outside air from entering the room. This condition is often utilized in clean rooms or operating theaters to minimize contamination from outside sources.

The other choices do not accurately describe positive air pressure. For instance, while air may flow into a room from outside under negative pressure conditions, this is not characteristic of positive pressure. The statement about no air movement is misleading, as there is indeed air movement related to the pressure differential. Regarding filtration, while air may be filtered in various systems, it does not define positive air pressure itself; rather, it is a different aspect of air quality management.