Question

What is the value of the 'U-value' in the context of building insulation and thermal performance?

• A. Measure of heat stored in a material
• B. Measure of thermal transmittance through a building element
• C. Measure of sound insulation
• D. Measure of structural strength

Hint:

Always remember: Lower U-value = better insulation = more energy-efficient building.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The U-value measures how much heat escapes through building components like walls, windows, and roofs.
Step 2: Key Formula or Approach:
The U-value is the inverse of the R-value (Thermal Resistance):
\[ U = \frac{1}{\sum R} \]
Unit: \(W/m^2K\).
Step 3: Detailed Explanation:
A lower U-value indicates that a material is a better insulator, meaning less heat energy is transmitted through it.
Higher U-values mean higher heat loss or gain, leading to poor energy efficiency.
Step 4: Final Answer:
U-value measures thermal transmittance.