Construction Supervisor License Practice Exam

How much air movement is acceptable between conditioned and unconditioned spaces at a pressure differential of 1.57 psf?

1. 1 cfm

2. 1½ cfm

3. 2 cfm

4. 2½ cfm

The correct answer is: 2 cfm

The correct answer, which is 2 cfm, relates specifically to the standard leakage rate for acceptable air movement through building components when there is a pressure differential of 1.57 pounds per square foot (psf). This pressure differential correlates to a typical testing standard used in evaluating air leaks in buildings, particularly in the context of energy efficiency and indoor air quality. In building construction, maintaining the right balance of air movement between conditioned (climate-controlled) spaces and unconditioned areas (such as attics or crawlspaces) is crucial for preventing unwanted drafts, moisture accumulation, and energy loss. The figure of 2 cfm at 1.57 psf represents an industry guideline that assists builders and inspectors in determining whether a structure meets certain performance criteria in terms of air tightness and energy efficiency. Acceptable air movement levels are governed by various codes and standards that aim to enhance the overall performance of buildings. The choice of 2 cfm reflects a practical threshold that aligns with what is generally recognized as favorable airflow to help maintain the integrity of conditioned spaces while still allowing for some necessary ventilation.