What is the required R-value insulation for supply air duct work run through a ventilated crawl space in climate zone 4?

• A. R-6
• B. R-8
• C. R-10
• D. R-12

Answer: (B)

For supply air ductwork located in a ventilated crawl space within climate zone 4, the required insulation level is R-8. This R-value is specifically designated for duct systems to enhance energy efficiency and prevent heat loss or heat gain, ensuring that the air being delivered through the ducts is at the desired temperature when it reaches its destination.

In climate zones, the insulation requirements are determined by both the temperature variations experienced in that climate and the construction practices in the region. Climate zone 4 typically experiences mild winters, but proper insulation of ducts helps maintain energy efficiency by reducing the energy needed to achieve and maintain comfort in living spaces.

Choosing R-8 for duct insulation in a ventilated crawl space helps mitigate potential energy loss while adhering to building codes and best practices for mechanical systems in that specific climate zone. It's important to reference local energy codes as they can dictate insulation requirements based on regional standards.