Indoor Air sciences CSMI Practice Exam

What is the recommended minimum pressure differential between containment and clean areas according to Bioaerosols and IICRC S520?

1. 0.02 inches mercury

2. 0.02 Pascals

3. 0.02 manometers

4. 0.02 inches water column

The correct answer is: 0.02 inches water column

The recommended minimum pressure differential of 0.02 inches water column is significant because it establishes a clear demarcation between containment areas, where potentially contaminated air may exist, and clean areas that need to remain unaffected by pollutants or bioaerosols. This pressure differential ensures that air flows from the clean areas to the containment area, preventing the escape of contaminants. Using inches of water column is a common practice for measuring small pressure changes in buildings and ensures accuracy in maintaining appropriate environmental conditions. In comparison, the other units provided are generally unrelated to air pressure measurement in this context. Pascals are a standard SI unit, but they wouldn't be as practical in comparing small differentials in the context of indoor air quality. Inches of mercury and manometers are also units of pressure, but they are less commonly used in practice for the specific purpose of determining pressure differentials in containment scenarios compared to inches of water column. Hence, the use of inches water column is most suitable for achieving optimal air quality management in indoor environments.