Building Code Administrators and Inspectors Florida Principle and Practice Licensure Practice Exam

According to building codes, what must not be interposed between the flexible duct and its collar fitting?

1. The outer jacket of a flexible duct section

2. Insulation material

3. A fire retardant barrier

4. A snap lock

The correct answer is: The outer jacket of a flexible duct section

The correct answer is based on the importance of maintaining the integrity and performance of the flexible duct connection to its collar fitting. The outer jacket of a flexible duct section is typically made from materials that are not designed to compress or deform significantly. If the outer jacket is placed between the flexible duct and the collar fitting, it can create an improper seal, which may lead to air leaks or reduced efficiency in the HVAC system. When ducts are installed, ensuring a tight and proper connection is critical for effective airflow and overall system performance. If insulation material, fire retardant barriers, or snap locks are placed at this connection point instead of the duct's outer jacket, they usually do not compromise airflow or create seal issues in the same way the outer jacket would. Understanding the specific roles and compatibility of these components is essential for meeting building code requirements and ensuring system efficiency.