What is the recommended R-value for a 1 inch thick polyisocyanurate insulation in cooling conditions?

What is the recommended R-value for a 1 inch thick polyisocyanurate insulation in cooling conditions?

• A. 4.0
• B. 5.60
• C. 6.0
• D. 7.0

Answer: (B)

R-value measures how well a material resists heat flow—the higher the number, the better the insulation. For polyisocyanurate insulation in cooling conditions, the commonly used per-inch rating is 5.60. That means a 1-inch thickness provides about R-5.60 of resistance. This value reflects how PIR behaves in cooler environments and is the standard figure used for designing in cooling applications. If you had more thickness, you’d add the same per-inch value for each inch (for example, two inches would give R-11.20).

R-value measures how well a material resists heat flow—the higher the number, the better the insulation. For polyisocyanurate insulation in cooling conditions, the commonly used per-inch rating is 5.60. That means a 1-inch thickness provides about R-5.60 of resistance. This value reflects how PIR behaves in cooler environments and is the standard figure used for designing in cooling applications. If you had more thickness, you’d add the same per-inch value for each inch (for example, two inches would give R-11.20).