Massachusetts Construction Supervisor License (CSL) Practice Test

What is the U-value of R-30 insulation?

1. 0.05

2. 0.02

3. 0.03

4. 0.01

The correct answer is: 0.03

The U-value is a measure of thermal transmittance and is the inverse of the R-value, which indicates thermal resistance. The R-value measures how well a building material can insulate against heat loss, and the U-value represents how much heat is transferred through a structure. To determine the U-value of R-30 insulation, you can use the formula: U-value = 1 / R-value In this case, the R-value is 30: U-value = 1 / 30 = 0.0333 This value is typically rounded to a more usable figure for practical applications, often approximated as 0.03. Thus, the U-value of R-30 insulation is approximately 0.03, which aligns with the chosen answer. Understanding this relationship between R-value and U-value is crucial for effective insulation evaluation and selection in construction and energy efficiency strategies.