ICC Commercial Mechanical Practice Exam

What must be the minimum and maximum size of a corrosion-resistant screen for outdoor air intake openings in residential occupancies?

1. 1/4 inch and 1/2 inch

2. 1/8 inch and 1/4 inch

3. 1/4 inch and 3/8 inch

4. 1/4 inch and 3/4 inch

The correct answer is: 1/4 inch and 1/2 inch

The correct answer identifies that the minimum and maximum size of a corrosion-resistant screen for outdoor air intake openings in residential occupancies must be between 1/4 inch and 1/2 inch. This sizing is important for multiple reasons related to the functionality and efficiency of the ventilation system. Having a screen with a minimum size of 1/4 inch is crucial to ensure that the screen effectively prevents entry of larger debris and pests while still allowing adequate airflow. If the mesh size is too large, there is a risk that insects or other contaminants could enter the ventilation system, potentially leading to clogging or health concerns. On the other hand, the maximum size of 1/2 inch serves to ensure that the screen does not impede airflow excessively. Air intake systems need to function efficiently to maintain indoor air quality and comfort, and a screen that is too dense could limit the amount of outdoor air entering the system, impacting performance. The correct answer reflects established standards in construction codes and practices to balance both protection and airflow, ensuring that residential ventilation systems operate effectively while minimizing the risk of contamination from the outdoors.