What does R-value measure?

What does R-value measure?

• A. Measures heat transfer coefficient
• B. Measures moisture content
• C. Measures air leakage
• D. Measures Thermal Resistance

Answer: (D)

R-value measures thermal resistance—the ability of a material or assembly to resist heat flow. A higher R-value means better insulation and less heat transfer through the structure. When you have multiple layers, you add each layer’s R-value to get the total, and the rate of heat transfer is determined by the temperature difference divided by that total resistance. This concept is about resisting heat flow, not about moisture content or air leaks. It’s also distinct from the heat transfer coefficient (the U-value), which directly describes how much heat crosses a surface per unit area per degree of temperature difference. In short, R-value is a measure of thermal resistance.

R-value measures thermal resistance—the ability of a material or assembly to resist heat flow. A higher R-value means better insulation and less heat transfer through the structure. When you have multiple layers, you add each layer’s R-value to get the total, and the rate of heat transfer is determined by the temperature difference divided by that total resistance. This concept is about resisting heat flow, not about moisture content or air leaks. It’s also distinct from the heat transfer coefficient (the U-value), which directly describes how much heat crosses a surface per unit area per degree of temperature difference. In short, R-value is a measure of thermal resistance.