Indoor Air sciences CSMI Practice Exam

How can you determine if a containment is under negative pressure?

1. Pressure inside is more than outside.

2. The enclosure billows out.

3. Pressure inside is less than outside.

4. Pressure outside is less than inside.

The correct answer is: Pressure inside is less than outside.

To ascertain whether a containment is under negative pressure, it is essential to analyze the relationship between the pressure inside the containment and the pressure outside it. When the pressure inside is less than the pressure outside, this creates a condition of negative pressure. This means that air from the outside environment is likely to be drawn into the containment, which is often a desired condition in scenarios where contaminants or pollutants must be contained and prevented from escaping into adjacent areas. In contrast, if the pressure inside were greater than that outside, it would indicate a positive pressure situation, where air would be pushed out of the containment rather than drawn in. Observing the enclosure billowing out can also indicate a positive pressure condition, while the situation where the outside pressure is less than the inside does not accurately describe negative pressure. Therefore, determining that the pressure inside is less than the pressure outside provides a clear understanding of negative pressure in containment.