R-value measures which property?

R-value measures which property?

• A. Thermal Conductivity
• B. Thermal Resistance
• C. Heat Capacity
• D. Insulation Thickness

Answer: (B)

R-value measures how well a material or assembly resists heat flow. It quantifies thermal resistance—the higher the R-value, the better the insulation resists heat transfer. This resistance increases with either greater thickness or lower thermal conductivity of the material, since R = thickness divided by k for a simple layer. It’s a property of how much heat transfer is slowed, not how much heat a material can store (that would be heat capacity). It’s also not the thickness itself, though thickness can boost R when paired with a given material’s conductivity.

R-value measures how well a material or assembly resists heat flow. It quantifies thermal resistance—the higher the R-value, the better the insulation resists heat transfer. This resistance increases with either greater thickness or lower thermal conductivity of the material, since R = thickness divided by k for a simple layer. It’s a property of how much heat transfer is slowed, not how much heat a material can store (that would be heat capacity). It’s also not the thickness itself, though thickness can boost R when paired with a given material’s conductivity.