Red Seal Sheet Metal Worker Practice Exam

What type of insulation is often used in ductwork?

1. Cellulose insulation

2. Foam board insulation

3. Rigid fiberglass

4. Loose fill insulation

The correct answer is: Rigid fiberglass

Rigid fiberglass insulation is commonly used in ductwork due to its excellent thermal performance and durability. This type of insulation provides a non-combustible, moisture-resistant, and effective barrier against heat loss or gain in HVAC systems. Its rigid structure allows for ease of installation within duct systems, ensuring a snug fit that minimizes gaps where energy loss could occur. Additionally, rigid fiberglass insulation helps to reduce noise transmission through the ducts, making it a preferred choice for maintaining sound comfort in buildings. Overall, the properties of rigid fiberglass make it an ideal material for insulating ductwork effectively and efficiently.