Red Seal Sheet Metal Worker Practice Exam

What is the purpose of a plenum in an HVAC system?

1. To store excess dust and debris

2. To help filter air contaminants

3. To distribute air to and from the HVAC unit

4. To indicate airflow directions

The correct answer is: To distribute air to and from the HVAC unit

The purpose of a plenum in an HVAC system is to distribute air to and from the HVAC unit. A plenum serves as a central hub for air, allowing for the efficient movement of conditioned air throughout the ductwork in a building. It can be either a supply plenum, which delivers heated or cooled air from the HVAC unit to various parts of the system, or a return plenum, which collects air from the occupied spaces and returns it to the HVAC unit for reconditioning. Having a system in place like a plenum ensures that air is evenly distributed, which is critical for maintaining temperature consistency and comfort within spaces. Additionally, by providing a common area for air circulation, plenums can help minimize noise from air movement and create a more efficient airflow path, improving the overall performance of the HVAC system. This aspect of air distribution is crucial for maintaining indoor air quality and comfort levels in various environments.