If R-value increases, what happens to U-value?

If R-value increases, what happens to U-value?

• A. U decreases
• B. U increases
• C. U remains the same
• D. U becomes negative

Answer: (B)

Increasing the R-value, which measures how strongly a component resists heat flow, lowers the U-value, which measures how much heat transfers per unit area per degree of temperature difference. This happens because U-value and R-value are reciprocal: U = 1/R. So if R-value goes up, the denominator gets larger and the overall U-value gets smaller. For example, doubling R from 5 to 10 reduces U from 0.2 to 0.1 (using the same units), meaning less heat is transferred. In practical terms, higher R-value means better insulation and a lower U-value. U-values can’t be negative; as R-value becomes very large, U-value approaches zero, and as R-value approaches zero, U-value becomes very large.

Increasing the R-value, which measures how strongly a component resists heat flow, lowers the U-value, which measures how much heat transfers per unit area per degree of temperature difference. This happens because U-value and R-value are reciprocal: U = 1/R. So if R-value goes up, the denominator gets larger and the overall U-value gets smaller. For example, doubling R from 5 to 10 reduces U from 0.2 to 0.1 (using the same units), meaning less heat is transferred. In practical terms, higher R-value means better insulation and a lower U-value. U-values can’t be negative; as R-value becomes very large, U-value approaches zero, and as R-value approaches zero, U-value becomes very large.